US09-04: Write the User Manual with Generated Screenshots

.dockerignore

@@ -9,6 +9,7 @@
 !photo_pipeline
 !migrations
 !frontend
+!docs
 !docker
 
 # Nothing generated, even under an allowed directory.

.gitattributes

@@ -0,0 +1,9 @@
+# Vendored third-party browser bundles (US09-01). Minified upstream files carry
+# trailing whitespace and very long lines; they are not ours to reformat, and the
+# submit gate's `git diff --check` would refuse them forever. Their integrity is
+# controlled where it belongs instead: a pinned version and a recorded sha256 in
+# frontend/js/vendor/VERSIONS.json, asserted by tests/integration/test_documentation.py.
+#
+# Only the whitespace check is turned off. They stay text, so a credential scan or a
+# search still reads them.
+frontend/js/vendor/*.js -whitespace linguist-vendored

Dockerfile

@@ -70,6 +70,8 @@ COPY pyproject.toml alembic.ini README.md ./
 COPY photo_pipeline ./photo_pipeline
 COPY migrations ./migrations
 COPY frontend ./frontend
+# The manuals are served by the application itself (US09-01), so they ship with it.
+COPY docs ./docs
 COPY docker/entrypoint.sh docker/healthcheck.sh /usr/local/bin/
 
 # Runtime dependencies only: the `test` extra (pytest, playwright) and the `vision`

docs/architecture.md

@@ -0,0 +1,224 @@
+# Architecture
+
+[← Documentation index](index.md)
+
+For whoever has to change this code without breaking somebody's photo library. It
+explains what the pieces are, which rules each one keeps, and where to look when a
+stage refuses.
+
+The product decisions behind all of it live in `INTEGRATED_PIPELINE_CONCEPT.md`; this
+page describes what was built.
+
+## Context
+
+Five things outside the application, and what actually crosses each boundary.
+
+```mermaid
+flowchart LR
+  operator([Operator]):::person -->|browser, one session| app
+  app[Photo Pipeline]:::system -->|read, rename, EXIF write| library[(Photo library<br/>bind mount)]
+  app -->|database, cache, journals, backups| data[(Data directory<br/>local filesystem)]
+  app -->|confirmed-SFW images only| vision[Vision provider]:::ext
+  app -->|immich-go, verified bytes| immich[Immich server]:::ext
+  app -->|copy, verify, then remove| archive[(Archive medium)]
+  classDef person fill:#1f6feb,stroke:#58a6ff,color:#fff
+  classDef system fill:#238636,stroke:#3fb950,color:#fff
+  classDef ext fill:#6e40c9,stroke:#a371f7,color:#fff
+```
+
+| boundary | leaves the machine? | carries |
+|---|---|---|
+| operator → app | no (loopback, or a proxy you configured) | commands against stable ids, never paths |
+| app → library | no | reads, folder renames, EXIF merges |
+| app → data directory | no | SQLite in WAL mode, thumbnails, journals, backups |
+| app → vision provider | **yes** | image bytes of confirmed-SFW canonical assets only |
+| app → Immich | **yes** | the exact verified bytes of an approved album |
+| app → archive medium | no | copies, verified before the source is removed |
+
+## Runtime
+
+Two long-lived processes and a one-shot migration, sharing one database and one
+library.
+
+```mermaid
+flowchart TD
+  browser([Browser]) -->|JSON + SSE| api
+  migrate["migrate<br/>backup, then upgrade"] -->|must exit 0| api
+  migrate --> worker
+  api["api · serve<br/>enqueues, serves, reads"] -->|jobs table| db[(SQLite WAL)]
+  worker["worker<br/>claims and does the work"] -->|jobs table| db
+  worker --> tools["exiftool · vision API · immich-go"]
+  api -.->|api.lock.json| lock{{library lock}}
+  worker -.->|worker.lock.json| lock
+  api --> lib[(library)]
+  worker --> lib
+```
+
+`serve` enqueues and renders; **it does not do the work**. Everything that scans,
+scores, analyses, renames, uploads, or archives happens in the worker, which claims
+a queued job atomically with a fencing token. One mutating job runs at a time, and
+the lock file in the data directory is what makes a second worker impossible rather
+than merely discouraged.
+
+## The modules
+
+| package | owns | must not |
+|---|---|---|
+| `api/` | HTTP surface, error envelope, security policy | contain SQL or business logic |
+| `api/routes/` | one module per resource group, all under `/api/v1` | accept a filesystem path from the browser |
+| `api/security.py` | host/origin/CSRF/session/size policy as one pure `evaluate`, plus the ASGI middleware | be bypassed per-route |
+| `schemas/` | Pydantic request and response contracts | reach the database |
+| `services/` | all domain logic; the only place a decision is made | be imported by the frozen CLI archive |
+| `models/` | SQLAlchemy tables | hold behaviour |
+| `jobs/` | durable job lifecycle, worker loop, lock ranks, handler registry | run work in the API process |
+| `integrations/` | the real outside world: `exiftool`, vision, NSFW model, `immich-go` and its report grammars | be called without a version recorded |
+| `path_policy.py` | the library boundary, `_IGNORE/` exclusion, symlink-escape refusal | be duplicated anywhere |
+| `imaging.py` | the single bounded-decode door | let a caller open an image directly |
+| `faults.py` | the crash barriers the tests fire | read anything but its one env var |
+| `config.py` | typed settings, secrets as `SecretStr` | log or return a value |
+| `db.py` | engine, sessions, WAL and foreign keys, migration entry | be used to bypass a repository |
+
+Services worth knowing by name: `inventory`, `duplicates`, `safety`, `analysis`,
+`albums`/`proposals`/`naming`, `renames`/`rename_apply`/`rename_journal`,
+`uploads`/`upload_batches`/`upload_reports`/`upload_verification`,
+`archives`/`archive_transfer`/`archive_journal`/`restores`/`availability`,
+`thumbnails`, `hashing`, `exif_checkpoint`, `jobs`, `workflow`, `backup`,
+`diagnostics`, `app_lock`, `release`, `benchmarks`, `library`, `legacy_import`.
+
+## The state machines
+
+Three journals decide what a restart is allowed to assume. All three are read from
+the database plus the real world — never guessed from a missing file.
+
+### Durable jobs
+
+```mermaid
+stateDiagram-v2
+  [*] --> queued
+  queued --> running: claimed with a fencing token
+  queued --> cancelled
+  queued --> cancelling
+  running --> succeeded
+  running --> failed
+  running --> cancelling
+  cancelling --> cancelled
+  failed --> retry_queued
+  retry_queued --> running
+  succeeded --> [*]
+  cancelled --> [*]
+```
+
+`succeeded` and `cancelled` are terminal, so a duplicate delivery cannot move a
+finished job. Claiming is compare-and-set on the row version; a worker whose lease
+expired cannot commit after another has taken over.
+
+### The rename journal
+
+The only state machine that moves somebody's folders.
+
+```mermaid
+stateDiagram-v2
+  [*] --> planned
+  planned --> moving
+  moving --> moved
+  moving --> planned: proven untouched
+  moving --> rollback_required
+  moved --> database_updated
+  database_updated --> verified
+  verified --> complete
+  moved --> rollback_required
+  database_updated --> rollback_required
+  verified --> rollback_required
+  planned --> failed
+  failed --> planned
+  rollback_required --> rolled_back
+  complete --> [*]
+  rolled_back --> [*]
+```
+
+Intent is written **before** the disk is touched, which is why `moving` can resolve
+backwards: the evidence decides. `moving`, `moved`, `database_updated`, and
+`rollback_required` are the unsafe states — while any operation sits in one, the
+library may be half-renamed, so unrelated mutations are refused with
+`409 rename_recovery_required` until a person resolves it.
+
+### Upload batches
+
+```mermaid
+stateDiagram-v2
+  [*] --> planned
+  planned --> running
+  running --> succeeded
+  running --> failed
+  running --> cancelling
+  running --> unknown_requires_verification: process died after acceptance
+  cancelling --> cancelled
+  failed --> running: retry
+  cancelled --> running: retry
+```
+
+`unknown_requires_verification` is deliberately **not** restartable. The server may
+already hold the files; the answer is to ask Immich for the recorded SHA-1, not to
+upload again and hope.
+
+Archive transfers use the same shape — `planned → transferring → verified →
+removing → complete` — and the source is removed only after the archived bytes are
+verified.
+
+## Identity and the data model
+
+A path is metadata. The identity is `assets.id`, a UUID that never changes, and
+`asset_paths` records every path an asset has ever had with the reason it changed.
+That is what makes a rename cheap: nothing else in the database has to move.
+
+Tables: `assets`, `asset_paths`, `thumbnails`, `jobs`, `job_items`, `job_events`,
+`safety_reviews`, `analysis_results`, `exif_projections`, `duplicate_clusters`,
+`duplicate_members`, `duplicate_negative_links`, `album_proposals`, `rename_plans`,
+`rename_operations`, `upload_batches`, `upload_items`, `upload_verifications`,
+`archive_locations`, `archive_plans`, `archive_operations`.
+
+Availability is independent of workflow progress: `active`, `archiving`,
+`archived_online`, `archived_offline`, `restoring`, `missing_unexpected`. An
+unmounted archive disk is `archived_offline`, never `missing` — the scanner is not
+allowed to conclude that a photo is gone because a disk is unplugged.
+
+EXIF is a projection with its own verified state (`verified`, `divergent`,
+`failed`): the desired values are written, read back, and compared, and anything the
+stage does not own having changed makes the asset `divergent` and blocks the next
+mutating stage.
+
+## Where each invariant lives
+
+| invariant | enforced in |
+|---|---|
+| `_IGNORE/` is never traversed, counted, or opened | `path_policy.is_excluded`, used by every discovery path |
+| no path outside the library roots is reachable | `path_policy.resolve_in_roots` — it returns the resolved path, because validating one name and opening another is the symlink race |
+| one writer per library | `services/app_lock.py` (an `flock` on a JSON lock file, per role) |
+| one mutating job at a time | `services/jobs.py` lock keys plus `jobs/locks.py` rank ordering |
+| only confirmed-SFW assets reach the vision provider | `services/analysis.py`, re-checked *after* the provider call so a decision that flipped mid-flight discards the result |
+| EXIF is verified, and other fields preserved | `services/exif_checkpoint.py` |
+| uploads carry the exact verified bytes | `services/uploads.py` preflight, re-proved immediately before the uploader runs |
+| an uncertain upload is not a failure | `services/upload_batches.py`, `services/upload_verification.py` |
+| the archive source outlives its copy until verified | `services/archive_transfer.py` |
+| decoding is bounded | `imaging.py` |
+| the trust boundary and CSRF | `api/security.py` |
+
+## Concurrency
+
+Locks are taken broad to narrow — `library → stage/job → album/folder → asset` — and
+never the other way, which is what makes deadlock structural rather than lucky.
+Ranks live in `jobs/locks.py`.
+
+Exactly-once execution is not achievable across SQLite, a filesystem, subprocesses,
+and a remote server. The design promises **at-least-once with idempotent recovery**:
+every handler may run twice, and running twice must not produce two side effects.
+That is why the rename journal records intent before moving, why EXIF writes merge
+and verify, and why upload retries consult both local history and Immich.
+
+## History
+
+This application was extracted from two command-line tools rather than written from
+nothing. Their sources are frozen in `legacy_cli_archive/` with the ledger mapping
+each donated behaviour to the service that now owns it, the characterization tests
+that pinned it, and every intentional difference. Production code must not import
+them; they are provenance and rollback evidence.

docs/errors.md

@@ -0,0 +1,95 @@
+# Errors and refusals
+
+[← Documentation index](index.md)
+
+Every error the API returns carries a code:
+
+```json
+{"error": {"code": "lock_held", "message": "a library_write job is already running"}}
+```
+
+Most of them are **refusals, not faults**. This application would rather stop and
+explain than guess about somebody's photographs, so a code below usually means it
+protected something. Each row says what caused it and what to do.
+
+## Access and the trust boundary
+
+| code | cause | what to do |
+|---|---|---|
+| `unauthenticated` | no application session | reload the page; the browser bootstraps one |
+| `access_denied` | wrong or missing access secret | check `PHOTO_PIPELINE_ACCESS_SECRET`. Attempts are logged with the caller's address only |
+| `too_many_attempts` | more than five failed secret attempts in a minute | wait. This is the rate limit, not a lockout |
+| `csrf_failed` | a mutation without the session's token | reload; a stale tab has an old token |
+| `host_not_allowed` | the `Host` header is not a configured name | add the real hostname to `PHOTO_PIPELINE_ALLOWED_HOSTS` |
+| `origin_not_allowed` | the request came from another origin | not something a browser tab of this app produces |
+| `cross_site_blocked` | another site triggered the request | expected — this is the protection working |
+| `payload_too_large` | the body exceeds `PHOTO_PIPELINE_MAX_REQUEST_BYTES` | send less; every endpoint takes small commands |
+| `path_not_allowed` | a path resolved outside the library roots | usually a symlink. Nothing outside the roots is reachable, by design |
+
+## The safety gate
+
+| code | cause | what to do |
+|---|---|---|
+| `dry_run_not_approved` | mutation is gated until a dry run is approved | run `dry-run`, read it, then `approve-dry-run` |
+| `approval_scope_mismatch` | the approval covers different library roots | approve a report for the roots actually configured |
+| `approval_unreadable` | the approval record cannot be read | re-approve; do not edit it by hand |
+
+## Concurrency and staleness
+
+| code | cause | what to do |
+|---|---|---|
+| `lock_held` | a mutating job already holds the lane | wait for it. One at a time is what makes a crash recoverable |
+| `version_conflict` | you acted on a version that changed underneath you | the view re-renders with the server's truth; decide again |
+| `invalid_transition` | a state change that the machine does not allow | usually a stale tab; reload |
+| `job_error` | the job service refused the request | the message says why |
+| `rename_recovery_required` | an interrupted rename is unresolved | resolve it in [Renames](stages/renames.md). Unrelated mutations stay blocked on purpose |
+
+## Stage refusals
+
+| code | cause | what to do |
+|---|---|---|
+| `nothing_to_score` | no photo is eligible for safety scoring | the queue is already decided |
+| `nothing_eligible` | no photo is eligible for analysis | resolve safety decisions first |
+| `nothing_to_plan` | no approved album name to build a plan from | approve a proposal first |
+| `invalid_decision` | the decision is not one this cluster accepts | reload the cluster |
+| `invalid_proposal` | the name is empty, reserved, or has forbidden characters | fix the name; the rules are in [Album proposals](stages/albums.md) |
+| `unknown_album` | the album is not a folder the library knows | rescan |
+| `cannot_apply` | the plan is invalid, stale, or another plan is unresolved | read the blockers in the preview |
+| `cannot_rollback` | the operation is complete or its preconditions no longer hold | rollback is recovery, not undo |
+
+## Upload
+
+| code | cause | what to do |
+|---|---|---|
+| `stale_preflight` | bytes changed between approval and running | re-run preflight; this is the check that stops the wrong bytes being uploaded |
+| `not_runnable` | the batch is in a state that must not be re-run | an uncertain batch is verified, never retried |
+| `requires_verification` | the outcome is unknown; the server may hold the files | verify against Immich, then resolve |
+| `changed_after_upload` | the file changed after a successful upload | uploading again may create or upgrade an asset |
+
+## Operations
+
+| code | cause | what to do |
+|---|---|---|
+| `backup_failed` | the snapshot could not be taken or verified | check free space and the message |
+| `invalid_retention` | a `--keep` value that is not a positive count | the newest backup is never pruned |
+| `not_found` | no such id | usually a stale link |
+
+## Generic
+
+| code | cause |
+|---|---|
+| `invalid_request` | the request body failed validation. Field names only — never the values, which end up in logs and screenshots |
+| `http_error` | a plain HTTP-level refusal, with its status |
+| `internal_error` | an unhandled error. The code is all you get; the traceback is in the server log, because it can carry paths and credentials |
+
+## Diagnostics warnings
+
+Not errors — reported by `diagnostics` and worth acting on. They are listed with
+their meanings in [Diagnostics](stages/diagnostics.md): `disk_low`, `disk_critical`,
+`cache_over_quota`, `wal_growth`, `tool_version_drift`, `legacy_process_active`, and
+`no_roots`.
+
+## Startup refusals
+
+Exit codes 2 to 5 are covered by the installation manual under
+[when it refuses to start](installation.md#when-it-refuses-to-start).

docs/first-pass.md

@@ -0,0 +1,66 @@
+# A guided first pass
+
+[← Documentation index](index.md)
+
+One library, from nothing to a verified upload. Each stage links to its own page; this
+is the order, and — more importantly — where the points of no return are.
+
+![The workflow home, with every stage and its counts](images/workflow.png)
+
+The workflow page is the home view and the honest summary: each stage shows its state,
+its counts, why it is blocked if it is, and the one action that moves it forward.
+
+| # | stage | reversible afterwards? |
+|---|---|---|
+| 0 | [Inventory](stages/inventory.md) | nothing was changed |
+| 1 | [Duplicate review](stages/duplicates.md) | yes — decisions can be changed, no file is deleted |
+| 2 | [Safety review](stages/safety.md) | the decision, yes; the EXIF keyword is a file write |
+| 3 | [Analysis](stages/analysis.md) | the result, yes; the caption and keywords are a file write |
+| 4 | [Album proposals](stages/albums.md) | yes — approving renames nothing |
+| 5 | [Renames](stages/renames.md) | **your folders move.** Recoverable, journaled, but real |
+| 6 | [Upload](stages/uploads.md) | **assets exist on the Immich server.** Not undone from here |
+| 7 | [Archive](stages/archive.md) | **originals leave active storage.** Restorable while the medium is reachable |
+| — | [Diagnostics](stages/diagnostics.md) | read-only, any time |
+
+## Before the first run
+
+Take a backup of the photo library itself. This application is careful — it previews,
+journals, and verifies — but it is the first time you are pointing it at your
+photographs, and a backup is cheaper than confidence.
+
+If the library is irreplaceable, turn on `PHOTO_PIPELINE_REQUIRE_DRY_RUN_APPROVAL`
+before anything else. Every mutating request is then refused until you have produced
+a read-only reconciliation report and approved it by name.
+
+## The pass
+
+1. **Scan.** Inventory → *Rescan*. Reads only. Check the count, and check that
+   nothing under `_IGNORE/` appears.
+2. **Resolve duplicates.** Exact byte matches can be accepted as recommended; anything
+   fuzzy gets looked at. Resolving first is what stops you paying to analyse the same
+   photo twice.
+3. **Decide safety.** Every canonical photo becomes `sfw` or `nsfw`. Nothing reaches
+   the vision provider until it is confirmed SFW — this is the gate the whole design
+   exists around.
+4. **Analyse.** Only confirmed-SFW photos. Each result is written to the database and
+   projected into EXIF, then read back and verified.
+5. **Propose album names.** Evidence from what was analysed. Edit anything you disagree
+   with. Approving changes no file.
+6. **Build the rename plan, read it, apply it.** The preview shows every old → new
+   path. This is where folders move.
+7. **Rescan.** Paths are reconciled; identities are unchanged.
+8. **Upload.** Preflight lists every blocker. The command is previewed without the API
+   key. One album at a time.
+9. **Verify.** An uncertain upload is not a failure and not a success — ask the server.
+10. **Archive** (optional). Copy, verify, and only then reclaim the space.
+
+Stop anywhere. Every stage is resumable, and closing the browser cancels nothing.
+
+## Two rules worth internalising
+
+**The application refuses more than it warns.** A refusal is not a fault; it is the
+design working. [Errors and refusals](errors.md) explains each one.
+
+**One long job at a time.** Browsing stays available while a job runs, but a second
+mutating job is refused — that is what makes a crash recoverable rather than
+ambiguous.

docs/index.md

@@ -0,0 +1,49 @@
+# Photo Pipeline documentation
+
+One local application that takes a photo library from discovery to a verified Immich
+upload: duplicate detection, safety review, content analysis, album naming, guarded
+renaming, upload, and archive — one visible, resume-safe workflow.
+
+These pages are readable three ways, and they are the same files each time: in the
+repository under `docs/`, on Gitea, and inside the running application under
+**Docs**. There is no separate copy to fall out of date.
+
+## Read in this order
+
+1. [Overview](overview.md) — what the application does, the stages it moves a photo
+   through, and the rules it will not break.
+2. [Installation and operations](installation.md) — host and container installation,
+   every setting, the first-run checklist, upgrades, backup and restore, and what
+   each refusal at startup means.
+3. [A guided first pass](first-pass.md) — one library from scan to verified upload,
+   with the point of no return named in each stage.
+4. [Architecture](architecture.md) — the context and runtime diagrams, what each
+   module owns, the three journals a restart reads, and where every invariant is
+   enforced.
+
+## The stages, one page each
+
+Every page answers the same four questions: what the stage is for, what you decide,
+what it changes on disk or on the server, and what it refuses.
+
+1. [Inventory and discovery](stages/inventory.md)
+2. [Duplicate review](stages/duplicates.md)
+3. [Safety review](stages/safety.md)
+4. [Analysis](stages/analysis.md)
+5. [Album proposals](stages/albums.md)
+6. [Renames](stages/renames.md)
+7. [Upload](stages/uploads.md)
+8. [Archive](stages/archive.md)
+9. [Diagnostics and library statistics](stages/diagnostics.md)
+
+## When something goes wrong
+
+- [Errors and refusals](errors.md) — every error code, what caused it, what to do.
+- [Recovery](recovery.md) — what the application resolves by itself, and what needs
+  you.
+
+## Conventions
+
+A page tells you what a stage **changes on disk or on the server** before it tells
+you how to run it. Refusals are documented as intentional: this application would
+rather stop and explain than guess about somebody's photographs.

docs/installation.md

@@ -0,0 +1,336 @@
+# Installation and operations
+
+[← Documentation index](index.md)
+
+From nothing to a running instance pointed at your photo library, and everything you
+need afterwards: upgrading, backing up, restoring, and understanding a refusal.
+
+Two ways to install. **Container** is the deployment this project builds and ships;
+**host** is what you want for development or a single machine you already manage.
+Both run the same two processes against the same database.
+
+> Read [what it will not do](overview.md#what-it-will-not-do) first. Several of the
+> steps below only make sense once you know which rules the application is keeping.
+
+## Before you start
+
+| you need | version | why |
+|---|---|---|
+| Python | 3.12 or newer | the application |
+| `exiftool` | 13.x (the image pins `13.25+dfsg-1`) | every EXIF read and write |
+| `immich-go` | 0.32.0 (pinned in the image) | the upload stage only |
+| Docker + the compose plugin | any current | the container installation only |
+| a vision provider key | — | the analysis stage only |
+
+You also need a photo library you can afford to be wrong about. Take a backup of it
+before pointing anything at it for the first time, and consider running with
+[`PHOTO_PIPELINE_REQUIRE_DRY_RUN_APPROVAL`](#the-settings) on.
+
+## Host installation
+
+```bash
+python3.12 -m venv .venv
+.venv/bin/pip install -e ".[vision]"     # drop [vision] for a review-only install
+```
+
+Configure it. Every setting is an environment variable; a `.env` file in the working
+directory is read at startup:
+
+```bash
+cp .env.example .env && $EDITOR .env
+```
+
+`.env.example` lists every variable with its default and no values at all. For a
+loopback installation you need exactly one:
+
+```bash
+PHOTO_PIPELINE_LIBRARY_ROOTS=/home/you/Pictures
+```
+
+Then migrate and start the two processes:
+
+```bash
+.venv/bin/python -m photo_pipeline migrate    # create or upgrade the database
+.venv/bin/python -m photo_pipeline serve      # API and browser app on 127.0.0.1:8000
+.venv/bin/python -m photo_pipeline worker     # second terminal
+```
+
+**Both processes are required.** `serve` enqueues work and renders the application;
+nothing is scanned, scored, analysed, renamed, uploaded, or archived without a
+worker. Open <http://127.0.0.1:8000/app/> and confirm the workflow page loads.
+
+### The configuration file
+
+`.env`, or any path named by `PHOTO_PIPELINE_ENV_FILE`. It is parsed, never executed:
+`KEY=value` lines, `#` comments, optional quotes, no interpolation and no `export`. A
+configuration file that can run code is a configuration file that can be a
+vulnerability.
+
+**Anything already exported in the shell wins.** The file is your standing
+configuration; the environment is the override for one run.
+
+The archived CLI's names still work, so an existing `photo_analyzer.env` can be used
+as it is:
+
+| in the file | applied as |
+|---|---|
+| `LLM_API_KEY` / `GEMINI_API_KEY` | `OPENAI_API_KEY` |
+| `LLM_BASE_URL` | `OPENAI_BASE_URL` |
+| `LIBRARY` | `PHOTO_PIPELINE_LIBRARY_ROOTS` |
+
+`.env` and `*.env` are gitignored and refused by the repository's safety checks. The
+file holds a real key; it must never be committed.
+
+## Container installation
+
+```bash
+cp .env.example .env && $EDITOR .env
+docker compose up -d --build
+```
+
+The composition is one `serve` container, one `worker` container, a one-shot
+`migrate` that both wait for, one bind-mounted library, and one named data volume.
+
+Three variables it cannot start without:
+
+| variable | is |
+|---|---|
+| `PHOTO_PIPELINE_LIBRARY_HOST_PATH` | the library on this host |
+| `PHOTO_PIPELINE_LIBRARY_ROOTS` | where that library is mounted **inside** the container |
+| `PHOTO_PIPELINE_ACCESS_SECRET` | required, because publishing a port means the app is reachable from outside the container |
+
+Set `PHOTO_PIPELINE_UID` and `PHOTO_PIPELINE_GID` to the owner of the library: what
+the containers rename and rewrite keeps that ownership.
+
+### The data volume
+
+The `data` volume holds the database, its write-ahead log, the thumbnail cache, the
+operation journals, and the backups. **It must stay on a local filesystem.** SQLite
+in WAL mode needs real local locking, so NFS, SMB, and network volume drivers do not
+slow it down — they corrupt it. The library bind mount has no such restriction.
+
+### Ports and reaching it
+
+The API port is published to `127.0.0.1` unless `PHOTO_PIPELINE_PUBLISH_ADDRESS` says
+otherwise. Being reachable *was* the authentication in earlier versions: whoever could
+open the port owned the library. So the moment the application answers to anything but
+loopback — a hostname, a proxy, `0.0.0.0` — the access secret becomes mandatory and
+`serve` refuses to start without it rather than publishing your photographs.
+
+Behind a reverse proxy:
+
+```bash
+PHOTO_PIPELINE_ALLOWED_HOSTS=photos.example.com
+PHOTO_PIPELINE_ACCESS_SECRET=…                  # python -c 'import secrets; print(secrets.token_urlsafe(32))'
+PHOTO_PIPELINE_TRUSTED_PROXIES=10.0.0.2         # only the proxy's own address
+```
+
+`X-Forwarded-Proto` and `X-Forwarded-Host` are believed only from a trusted-proxy
+address, so a client cannot declare its own origin. The browser asks for the secret
+once per tab. Wrong secrets are rate-limited and logged with the caller's address
+only. The health endpoints stay open so an orchestrator can restart the container;
+nothing else is.
+
+### Deployment
+
+The stack is managed from git by Portainer, which redeploys on a webhook after CI
+publishes an image built from `main`. Runtime secrets live in the Portainer stack's
+environment rather than in the repository, so rotation happens in one place and
+reading the repository discloses nothing.
+
+## The settings
+
+Every variable, its default, and whether it is a secret. `.env.example` is the same
+list in copyable form.
+
+### Library and data
+
+| variable | default | meaning |
+|---|---|---|
+| `PHOTO_PIPELINE_LIBRARY_ROOTS` | none | the library boundary, `os.pathsep`-separated. No path outside these roots is ever read or written |
+| `PHOTO_PIPELINE_DATA_DIR` | `data` | database, WAL, thumbnail cache, journals, backups. Never inside the library |
+| `PHOTO_PIPELINE_DB_PATH` | `<data dir>/photo_pipeline.db` | the database file, if it must live elsewhere |
+| `PHOTO_PIPELINE_ENV_FILE` | `.env` | where to read the configuration file from |
+
+### Serving and the trust boundary
+
+| variable | default | meaning |
+|---|---|---|
+| `PHOTO_PIPELINE_HOST` | `127.0.0.1` | bind address |
+| `PHOTO_PIPELINE_PORT` | `8000` | port |
+| `PHOTO_PIPELINE_ALLOWED_HOSTS` | none | comma-separated names the app answers to besides loopback. Naming one makes the access secret mandatory |
+| `PHOTO_PIPELINE_ACCESS_SECRET` | none | **secret.** Traded for the session cookie at `GET /api/v1/session` |
+| `PHOTO_PIPELINE_TRUSTED_PROXIES` | none | comma-separated peer addresses whose forwarded headers may be believed |
+| `PHOTO_PIPELINE_MAX_REQUEST_BYTES` | `1048576` | largest request body accepted |
+
+### Logging
+
+| variable | default | meaning |
+|---|---|---|
+| `PHOTO_PIPELINE_LOG_LEVEL` | `INFO` | standard Python levels |
+| `PHOTO_PIPELINE_LOG_FORMAT` | `json` | `json` or `text` |
+
+### Limits
+
+| variable | default | meaning |
+|---|---|---|
+| `PHOTO_PIPELINE_THUMBNAIL_CACHE_QUOTA_BYTES` | `500000000` | cache quota; over it is a diagnostics warning |
+| `PHOTO_PIPELINE_THUMBNAIL_MAX_PIXELS` | `100000000` | refuse to decode anything larger. This is the decompression-bomb guard |
+| `PHOTO_PIPELINE_ARCHIVE_FREE_SPACE_RESERVE_BYTES` | `1000000000` | free space an archive destination must keep beyond the transfer itself |
+
+### The safety gate
+
+| variable | default | meaning |
+|---|---|---|
+| `PHOTO_PIPELINE_REQUIRE_DRY_RUN_APPROVAL` | `false` | refuse every mutating request until a read-only dry run of this library has been produced and approved |
+
+### External services
+
+| variable | default | meaning |
+|---|---|---|
+| `PHOTO_PIPELINE_VISION_API_KEY` | none | **secret.** Without it the analysis stage cannot run |
+| `PHOTO_PIPELINE_IMMICH_SERVER_URL` | none | the Immich server |
+| `PHOTO_PIPELINE_IMMICH_API_KEY` | none | **secret.** |
+| `PHOTO_PIPELINE_IMMICH_GO_BINARY` | `immich-go` | the uploader, found on `PATH` |
+
+### Composition only
+
+Read by `docker-compose.yml`, not by the application:
+`PHOTO_PIPELINE_IMAGE`, `PHOTO_PIPELINE_LIBRARY_HOST_PATH`,
+`PHOTO_PIPELINE_PUBLISH_ADDRESS`, `PHOTO_PIPELINE_UID`, `PHOTO_PIPELINE_GID`.
+
+A secret is never written to a log, never returned by the API, never stored in the
+database, and never recorded in a backup manifest — a manifest says `configured`, not
+the value. Do not put a real key in an example, a ticket, or a screenshot.
+
+## First run checklist
+
+Not "it started" — verified.
+
+1. **The database is at the current revision.**
+   `python -m photo_pipeline migrate` exits 0.
+2. **The application answers.**
+   `curl -s localhost:8000/api/v1/health/ready` returns 200.
+3. **The library was found.** Open the app, run a scan from the Inventory view, and
+   check the count against what you expect. Anything under `_IGNORE/` must be missing
+   from it — that is the exclusion working, not a bug.
+4. **The worker is claiming.** The scan job reaches `succeeded`. If it stays
+   `queued`, no worker is running.
+5. **Diagnostics are clean.**
+   `python -m photo_pipeline diagnostics` reports free space and an empty `warnings`.
+6. **Nothing was modified.** The scan is read-only; your files' timestamps are
+   unchanged.
+
+Only then point it at the whole library.
+
+## Operations
+
+Every operation is the same CLI, on a host or in the composition:
+
+```bash
+python -m photo_pipeline diagnostics
+docker compose run --rm --no-deps api diagnostics
+```
+
+`--no-deps` keeps a one-off command from starting a second stack; `api` is only the
+service it borrows the image and mounts from.
+
+### Upgrading
+
+1. `python -m photo_pipeline backup --reason before-upgrade`
+2. Pull the new version (or `docker compose pull && docker compose up -d`).
+3. Migrations run by themselves at startup, and a **pending schema change is
+   snapshotted first**. If the upgrade fails, the previous database and its
+   `pre-migration` backup are both intact, and the error log names the backup
+   directory.
+
+An up-to-date database is not backed up again on every start.
+
+### Backing up
+
+```bash
+python -m photo_pipeline backup --reason weekly --keep 7
+python -m photo_pipeline verify-backup data/backups/<name>
+```
+
+Backups go through SQLite's online backup API, never a file copy: with WAL enabled
+the `.db` file alone is missing every committed page still in the write-ahead log.
+Each backup is a directory holding the snapshot and a `manifest.json` — schema
+revision, SHA-256, row counts, the archive media the library depends on, and which
+settings were configured.
+
+`verify-backup` runs `PRAGMA integrity_check` **and** `PRAGMA foreign_key_check`,
+compares the snapshot's SHA-256 against the manifest, and re-counts every table it
+recorded. Bit rot, a truncated copy, and a "repaired" snapshot all fail it.
+
+`--keep N` prunes the oldest and never the newest. The same is available at
+`GET /api/v1/diagnostics`, `GET|POST /api/v1/backups`,
+`GET /api/v1/backups/{name}/verify`, and `POST /api/v1/backups/prune`.
+
+### Restoring
+
+Restore is deliberately **not** an API call. It replaces the state of an
+installation, so it belongs to a stopped one and a person at a terminal.
+
+1. Stop `serve` and `worker`.
+2. `python -m photo_pipeline verify-backup data/backups/<name>` — never restore an
+   unverified snapshot, and `restore` will refuse one anyway.
+3. `python -m photo_pipeline restore data/backups/<name> --into /path/to/fresh-data`.
+   A target that already holds a database is refused; recovering in place means
+   moving the old data directory aside first.
+4. Point `PHOTO_PIPELINE_DATA_DIR` at the restored directory and run `migrate`.
+5. Run an inventory scan, so paths are reconciled against the real library.
+6. Mount every archive location the manifest names before archiving again. The
+   database records where archived originals are; it does not contain them.
+
+Practise this against a copy before you need it.
+
+### Watching it
+
+`diagnostics` reports the database, write-ahead log, thumbnail cache, uploader
+reports, backups, and logs separately, with free space and warnings for low disk
+(`disk_low`, `disk_critical`), a cache over its quota, a write-ahead log outgrowing
+its database, and a legacy CLI writing the library.
+
+Logs go to stdout in JSON by default — `docker compose logs -f worker`, or your
+service manager's journal on a host. Uploader output is kept per attempt under the
+data directory with the API key scrubbed line by line.
+
+## When it refuses to start
+
+Every refusal below is deliberate. The application would rather stop and explain than
+guess about somebody's photographs.
+
+| exit code | meaning | what to do |
+|---|---|---|
+| `1` | the operation failed and said why — an unverifiable backup, an occupied restore target, an unknown benchmark profile | read the message; nothing was changed |
+| `2` | **the library lock is held.** Another `serve` or `worker` owns this data directory | stop the other process. The message names the holder; a lock whose process is gone is taken over automatically |
+| `3` | **a legacy CLI looks active.** The frozen command-line tools are writing this library | stop them. `--allow-legacy` overrides and you own the outcome |
+| `4` | **configuration refused.** The application is reachable beyond loopback and no access secret is set | set `PHOTO_PIPELINE_ACCESS_SECRET`, or bind to loopback only |
+| `5` | **a library root is not mounted** (containers only) | fix the bind mount. Refusing is what stops the container writing into its own throwaway layer instead of your library |
+
+Other things that look like faults and are not:
+
+- **`403 host_not_allowed`** — the `Host` header is not a name in
+  `PHOTO_PIPELINE_ALLOWED_HOSTS`. Add the real hostname; do not add `*`.
+- **`409 lock_held`** — a mutating job is already running. One at a time is what
+  makes a crash recoverable.
+- **`409 rename_recovery_required`** — an interrupted rename is unresolved. Resolve
+  it in the Renames view; unrelated mutations stay blocked until then, on purpose.
+- **A job stuck in `queued`** — no worker is running.
+- **An empty scan** — check `PHOTO_PIPELINE_LIBRARY_ROOTS`, and in a container check
+  that the path is the *container-side* mount, not the host path.
+
+## What an installer must not work around
+
+- **One writer.** Do not run two workers, and do not run the frozen CLI beside the
+  application. Each is safe alone and destructive together — the lock is not
+  bureaucracy.
+- **`_IGNORE/` is never read.** Do not "fix" the exclusion.
+- **EXIF is verified before upload.** Do not skip the checkpoint to make a stage
+  finish; an unverified projection is exactly the case where the wrong bytes reach
+  Immich.
+- **The data directory is not the library.** Keep them apart, and keep the data
+  directory on a local filesystem.
+- **Secrets stay in the environment.** Not in the database, not in a log, not in a
+  commit.

docs/overview.md

@@ -0,0 +1,77 @@
+# Overview
+
+[← Documentation index](index.md)
+
+Photo Pipeline sorts a photo library. It finds duplicates before anything expensive
+happens to them, asks a human which pictures may leave the machine, describes the
+ones that may, proposes album names from what it found, renames folders under a
+crash-safe journal, uploads through `immich-go`, and can archive a finished album off
+active storage without ever forgetting it existed.
+
+It runs locally. It talks to exactly three things outside itself: a vision provider,
+an Immich server, and `exiftool` — and it will tell you before it uses any of them.
+
+## The workflow
+
+Each stage is a gate, not a tab. A later stage can always be looked at; its actions
+stay disabled until what they depend on is true.
+
+```mermaid
+flowchart TD
+  I["0 · Inventory<br/>discover, hash, cluster duplicates"] --> S["1 · Safety<br/>score and human decision"]
+  S -->|sfw| A["2 · Analysis<br/>vision provider, EXIF checkpoint"]
+  S -->|nsfw| U
+  A --> B["3 · Albums<br/>proposal, then guarded rename"]
+  B --> U["4 · Upload<br/>immich-go, verified bytes"]
+  U --> R["5 · Archive<br/>copy, verify, then reclaim space"]
+```
+
+| Stage | What it decides | What it changes |
+|---|---|---|
+| Inventory | which file is the canonical copy of a picture | nothing — it only reads |
+| Safety | whether a photo may be sent to a cloud provider | one `sfw`/`nsfw` EXIF keyword |
+| Analysis | what a photo shows | a managed caption segment and additive keywords |
+| Albums | what a folder should be called | folder names, through a journaled rename |
+| Upload | which exact bytes reach Immich | nothing locally; assets appear in Immich |
+| Archive | which album leaves active storage | files move to the archive, after verification |
+
+## What it will not do
+
+These are enforced in code, not by convention, and each one is why some action you
+expected is sometimes refused.
+
+- **Nothing under `_IGNORE/` is ever read.** Not scanned, not counted, not
+  thumbnailed, not sent anywhere.
+- **A path is not an identity.** Every picture has a stable id, so moving or renaming
+  it loses no history.
+- **Only a confirmed-SFW photo reaches the vision provider.** A photo marked NSFW is
+  still uploadable to Immich; it simply never leaves for analysis.
+- **Metadata is verified, not hoped for.** Every stage that writes EXIF reads it back
+  and proves that what it did not own is unchanged.
+- **One writer at a time.** A library lock, held by one process, is what makes a
+  crash recoverable instead of ambiguous.
+- **Nothing irreversible happens without a preview and an explicit approval** that
+  names the exact count.
+
+## Where things live
+
+| | |
+|---|---|
+| the photo library | wherever you point `PHOTO_PIPELINE_LIBRARY_ROOTS`; mounted read-write |
+| the database, cache, logs, backups | the data directory, never inside the library |
+| secrets | the environment, never the database and never a log line |
+| these documents | `docs/` in the repository, served at `/docs` by the application |
+
+## Running it
+
+The short version, for a host installation:
+
+```bash
+python -m photo_pipeline migrate
+python -m photo_pipeline serve      # the API and this browser application
+python -m photo_pipeline worker     # the process that does the long work
+```
+
+The full procedure, the container path, and every setting are in the
+[installation manual](installation.md); if you would rather start using it, take
+[the guided first pass](first-pass.md).

docs/recovery.md

@@ -0,0 +1,62 @@
+# Recovery
+
+[← Documentation index](index.md)
+
+What the application resolves by itself, and what needs you. The dividing line is
+simple: it resumes when the evidence is unambiguous, and it stops and asks when it is
+not. It never guesses about your files.
+
+## An interrupted rename
+
+A rename records its intent **before** touching the disk, so after a crash the
+journal plus the actual filesystem give a verdict per operation:
+
+| verdict | means | what happens |
+|---|---|---|
+| resumable | the move provably did not happen | reset to planned and run again |
+| rollback-safe | the move happened; the remaining steps can be completed or undone | drive it forward, or roll it back |
+| manual | the evidence is contradictory | left alone, and it keeps blocking |
+
+Open [Renames](stages/renames.md); the recovery panel lists every unresolved
+operation and offers a resolve action only where one is safe. Until then, unrelated
+mutations are refused with `rename_recovery_required` — building new work on a
+half-applied move is how a library becomes unexplainable.
+
+## An uncertain upload
+
+`unknown_requires_verification` means the uploader died after Immich may have
+accepted the files. It is **not** retryable. Verification asks the server whether it
+holds the recorded SHA-1 and answers present, absent, or inconclusive. An
+inconclusive answer is resolved by you, with your evidence and name recorded in the
+batch's history.
+
+## A failed migration
+
+A pending schema change is snapshotted before it is applied. If the upgrade fails,
+the previous database and its `pre-migration` backup are both intact and the error
+log names the backup directory. Stop everything and run the
+[restore drill](installation.md#restoring).
+
+## A restored backup
+
+After restoring, run a scan. Paths are reconciled against the real library and
+identities are preserved where hashes match. Anything that does not match becomes a
+visible `stale` or `divergent` state instead of being quietly accepted.
+
+Mount every archive medium the manifest names before archiving again: the database
+records where archived originals live, it does not contain them.
+
+## A job that will not start
+
+Check, in this order: is a worker running; is another mutating job holding the lane
+(`lock_held`); is an interrupted rename blocking everything
+(`rename_recovery_required`); is the library lock held by a process that is still
+alive (exit code `2` names the holder).
+
+## What is never automatic
+
+No file is deleted, no folder is renamed, no upload is retried, and no archive source
+is removed without either an explicit confirmation from you or a verification the
+application performed itself. If you are reading this page because something happened
+that you did not approve, that is a bug worth reporting — with the diagnostics output
+and the relevant journal, both of which are safe to share: they carry no secrets.

docs/stages/albums.md

@@ -0,0 +1,47 @@
+# Album proposals
+
+[← Documentation index](../index.md) · [Guided first pass](../first-pass.md)
+
+![Reviewing an album proposal](../images/albums.png)
+
+**What it is for.** Turning a folder of analysed photographs into a name a person
+would have chosen, before any folder is touched.
+
+**What you decide.** The final name. The proposal is a starting point with its
+reasoning attached; you edit it, accept it, or ignore it.
+
+**What it changes.** A row per album: proposed name, rationale, confidence, and your
+final name, with a version. **Approving renames nothing.** Not one file moves at this
+stage — approval only marks a name as agreed, and the [rename stage](renames.md) is
+where it becomes a plan you have to confirm separately.
+
+**What it refuses.** A name containing `/ \ : * ? " < > |`, a reserved device name, or
+one that collides with an existing folder is rejected while you type and again on the
+server. Approval is refused when the evidence changed since the proposal was
+generated — the proposal is stale, and regenerating is the honest fix. Editing with a
+stale version returns a conflict and shows you the server's truth rather than
+overwriting it.
+
+## Reading the view
+
+The left pane lists albums with their state: `none`, `proposed`, `edited`,
+`approved`, `error`, or `stale`. The right pane shows the evidence the name was built
+from — date range, dominant tags, locations, counts — then the suggested name, the
+rationale, the confidence, and an editable final name.
+
+The default naming shape is predictable and sortable:
+
+```text
+YYYY-MM — Place — Event
+YYYY — Event
+Place — Event
+```
+
+## While a rename is unresolved
+
+Generating and approving proposals is blocked while an interrupted rename is
+outstanding, with `409 rename_recovery_required`. Resolve the rename first: building
+new names on top of a half-applied move is how a library becomes hard to reason
+about.
+
+Next: [renames](renames.md).

docs/stages/analysis.md

@@ -0,0 +1,39 @@
+# Analysis
+
+[← Documentation index](../index.md) · [Guided first pass](../first-pass.md)
+
+![The analysis view](../images/analysis.png)
+
+**What it is for.** Describing what a photograph shows, so albums can be named from
+evidence and the library can be searched by content.
+
+**What you decide.** When to run it, and over what scope. The descriptions themselves
+come from the configured vision provider.
+
+**What it changes.** For each eligible photo: a stored result — description, tags,
+approximate year, location hint, model and prompt version — and then an EXIF
+checkpoint that merges a **managed caption segment** and additive keywords into the
+file, reads them back, and verifies that nothing else moved. The file's SHA-256 is
+refreshed after the write.
+
+**What it refuses.** Anything not confirmed SFW. Anything not canonical. A malformed
+provider response is quarantined rather than stored. Keywords are only ever added,
+never removed, because EXIF keywords carry no ownership and deleting a generated one
+could delete yours.
+
+## Running it
+
+The view shows eligible, analysed, pending, and error counts, and the job's live
+progress. Starting a second mutating job while it runs is refused — that is the
+one-writer rule, not a queue.
+
+Cancelling drains safely: completed items stay completed, and resuming continues
+rather than restarting. A photo may be sent to the provider twice if a crash happens
+mid-item, but its stored result and its EXIF are written once.
+
+## Costs
+
+Each analysed photo is a provider call. Resolving duplicates first is what keeps that
+number honest, and the counts here are the ones to check before starting a large run.
+
+Next: [album proposals](albums.md).

docs/stages/archive.md

@@ -0,0 +1,43 @@
+# Archive
+
+[← Documentation index](../index.md) · [Guided first pass](../first-pass.md)
+
+![Archive locations and plans](../images/archive.png)
+
+**What it is for.** Moving a finished album out of active storage onto another disk,
+while keeping everything the library knows about it.
+
+**What you decide.** Which album, which destination, and whether to accept the
+reclaimed space in exchange for needing that medium mounted to see the originals
+again.
+
+**What it changes.** Files are copied to the archive location, verified there, and
+only then removed from the library. The asset keeps its id, its hashes, its
+decisions, its analysis, its upload history, and a durable preview thumbnail;
+`current_path` becomes null and availability becomes `archived_online` or
+`archived_offline`.
+
+**What it refuses.** Preflight blocks on: an unverified upload, a checksum that no
+longer matches the uploaded bytes, an unmounted or unwritable destination,
+insufficient free space plus the configured reserve, a destination that already
+holds unexpected paths, a missing durable thumbnail, and any conflicting job. The
+source is **never** removed before the archived copy is verified — not because Immich
+reported success, which is an ingest, not a backup.
+
+## Offline is not missing
+
+An archived photo whose medium is unplugged is `archived_offline`. It still appears
+in search, still participates in duplicate detection through its retained hashes and
+thumbnail, and is never reported as lost. If a full-resolution comparison is needed,
+the application asks you to mount the named medium rather than guessing.
+
+## Restore
+
+Restore is planned and journaled like everything else: the medium must be online, the
+bytes are copied back and verified into a collision-free destination, a new active
+path is registered, and a reconciliation scan follows. Existing safety, analysis,
+EXIF, and upload state stay valid when hashes match — and when they do not, the
+result is a visible `divergent` state rather than silent acceptance of a different
+file.
+
+Next: [diagnostics](diagnostics.md).

docs/stages/diagnostics.md

@@ -0,0 +1,49 @@
+# Diagnostics and library statistics
+
+[← Documentation index](../index.md) · [Guided first pass](../first-pass.md)
+
+![Library statistics](../images/statistics.png)
+
+**What it is for.** Answering "is this installation healthy, and what is in this
+library?" — the first thing to look at when a stage behaves unexpectedly.
+
+**What you decide.** Nothing. Both are read-only.
+
+**What it changes.** Nothing.
+
+**What it refuses.** Nothing — both are reads, and both stay available while a job
+holds the library. That is deliberate: the moment you most need to know what the
+installation is doing is while it is busy.
+
+## Statistics
+
+The Stats view summarises the library itself: how many photos are analysed, the
+common tags, the distribution across albums and years. It answers questions about
+your photographs.
+
+## Diagnostics
+
+Diagnostics answers questions about the *installation*, and lives at
+`GET /api/v1/diagnostics` and on the command line:
+
+```bash
+python -m photo_pipeline diagnostics
+```
+
+It reports the database, write-ahead log, thumbnail cache, uploader reports, backups,
+and logs as separate sizes, plus free space, the tool versions it found against the
+ones the image pinned, and which locks are held and by whom.
+
+Its warnings are the ones worth acting on:
+
+| warning | means |
+|---|---|
+| `disk_low` / `disk_critical` | free space is running out; mutating stages stop before the reserve |
+| `cache_over_quota` | the thumbnail cache exceeds its configured quota |
+| `wal_growth` | the write-ahead log is outgrowing its database — usually a long-running reader |
+| `tool_version_drift` | the installed `exiftool` or `immich-go` is not the version the image pinned |
+| `legacy_process_active` | the frozen command-line tools are writing this library. Stop them |
+| `no_roots` | no library root is configured, so there is nothing to work on |
+
+An empty `warnings` list on a fresh installation is what the
+[first-run checklist](../installation.md#first-run-checklist) is looking for.

docs/stages/duplicates.md

@@ -0,0 +1,36 @@
+# Duplicate review
+
+[← Documentation index](../index.md) · [Guided first pass](../first-pass.md)
+
+![The duplicate cluster list](../images/duplicates.png)
+
+**What it is for.** Deciding which file is *the* copy of a picture, before anything
+expensive or irreversible happens to the others.
+
+**What you decide.** For each cluster: keep the recommended canonical, choose a
+different one, keep everything as variants, declare it not a duplicate, or defer.
+
+**What it changes.** Only the decision, recorded as an auditable event. **No file is
+ever deleted.** Non-canonical copies stay exactly where they are; they are simply
+excluded from analysis and upload.
+
+**What it refuses.** Exact byte and identical-pixel matches may be accepted on the
+recommendation. Anything fuzzy — a crop, a re-encode, a burst frame — requires an
+explicit confirmation, because a perceptual hash is evidence, not proof.
+
+## Reading a cluster
+
+Each member shows its path, role, pHash distance, and size, with synchronised zoom
+across the previews. The recommendation is visible but never pre-applied for fuzzy
+matches. The confidence band tells you how much the machine is claiming.
+
+Rejecting a pair records a negative link, so a later rescan does not keep proposing
+the same wrong match.
+
+## Why first
+
+Resolving duplicates before safety and analysis is what stops you reviewing and
+paying for the same photograph three times. It also means the album evidence is built
+from one copy of each picture rather than a skewed count.
+
+Next: [safety review](safety.md).

docs/stages/inventory.md

@@ -0,0 +1,39 @@
+# Inventory and discovery
+
+[← Documentation index](../index.md) · [Guided first pass](../first-pass.md)
+
+![The inventory view](../images/inventory.png)
+
+**What it is for.** Finding every supported photo in the configured library roots and
+giving each one a permanent identity, so that everything afterwards can refer to a
+picture rather than a path.
+
+**What you decide.** Nothing. This stage is the only one with no judgement in it.
+
+**What it changes.** On disk, nothing at all — discovery reads. In the database it
+records each photo's path, size, timestamps, full-file SHA-256, normalised pixel hash,
+and perceptual hash, and it opens a path-history entry.
+
+**What it refuses.** Anything under an `_IGNORE/` directory is never traversed,
+counted, hashed, or previewed. Unsupported extensions and unreadable files are
+reported rather than skipped silently. Nothing outside the configured roots is
+reachable, including through a symlink.
+
+## Reading the view
+
+Each row is one asset: its current path, availability, whether the file is present,
+and its size. The filter searches paths; the availability selector separates active
+photos from archived ones.
+
+A **rescan** after moving files around outside the application is the normal way to
+reconcile: a file that moved keeps its identity, because identity is the hash and the
+id, not the location.
+
+## What good looks like
+
+The count matches what you expect, `_IGNORE/` contents are absent, and nothing shows
+as missing. A photo listed as missing means the file is no longer at its recorded
+path and no new path matched its hashes — that is a question for you, not something
+the scanner resolves by guessing.
+
+Next: [duplicate review](duplicates.md).

docs/stages/renames.md

@@ -0,0 +1,46 @@
+# Renames
+
+[← Documentation index](../index.md) · [Guided first pass](../first-pass.md)
+
+![The rename plan preview](../images/renames.png)
+
+**What it is for.** Applying approved album names to the actual folders — the first
+stage that changes your filesystem.
+
+**What you decide.** Whether to apply the plan, after reading it. The confirmation
+names the plan, its version, and its checksum, so what you approve is what runs.
+
+**What it changes.** Folders move. For each operation: the intent is journaled
+*before* the disk is touched, the move is made, `assets.current_path` is updated by
+id in one transaction, the old path is closed and a new one opened in path history,
+the result is verified, and only then is the operation complete.
+
+**What it refuses.** A plan is invalid — not merely warned about — when a source is
+missing or changed, two operations target the same destination, a destination already
+exists, a path would leave the library or enter `_IGNORE/`, or a source is a symlink.
+Case-only renames and cross-filesystem moves are allowed but flagged, because they
+take a different, staged route. A plan whose checksum no longer matches is refused
+rather than reinterpreted.
+
+## Reading the preview
+
+Every operation shows both full paths, the kind of move (`rename`, `case-only
+rename`, `cross-filesystem move`), how many photos it affects, its journal state, and
+any issue with its severity. The plan can be exported as JSON before you commit to it.
+
+**A run cannot be stopped part-way.** It can be interrupted — by a crash, a power
+cut, a killed container — and interruption is recoverable, but there is no cancel
+button once it starts. That is stated on the confirmation, not hidden in a manual.
+
+## After an interruption
+
+The recovery panel lists each unresolved operation with a verdict read from the
+journal *and the disk*: resumable, safely rollbackable, or needing a person. It never
+guesses from a missing path alone. Until it is resolved, unrelated mutations are
+refused with `409 rename_recovery_required`.
+
+Rollback is recovery, not undo. A completed operation is terminal — the button only
+appears for operations that are actually reversible. See
+[recovery](../recovery.md).
+
+Next: [upload](uploads.md).

docs/stages/safety.md

@@ -0,0 +1,43 @@
+# Safety review
+
+[← Documentation index](../index.md) · [Guided first pass](../first-pass.md)
+
+![The safety review queue](../images/safety.png)
+
+**What it is for.** Deciding which photographs may be sent to a cloud vision
+provider. This is the privacy gate the rest of the design is built around.
+
+**What you decide.** `sfw`, `nsfw`, or defer — per photo, or in bulk from the filters.
+A local model can score first to order the queue, but the score is a suggestion; the
+decision is yours.
+
+**What it changes.** The decision is stored in the database *and* projected into the
+file: one mutually exclusive `sfw` or `nsfw` keyword written into `Keywords` and
+`Subject`. The write is merged with existing metadata, read back, and verified, and
+the file's SHA-256 is refreshed afterwards.
+
+**What it refuses.** An undecided or deferred photo does not reach the vision
+provider, and does not reach Immich either. If the read-back shows that a field the
+stage does not own has changed, the checkpoint is marked `divergent`, the asset is not
+marked verified, and the next mutating stage is blocked rather than proceeding on
+metadata nobody trusts.
+
+## The rule that matters
+
+> Only a confirmed `sfw` photo may enter cloud content analysis. A confirmed `nsfw`
+> photo skips analysis entirely but remains eligible for upload to Immich once its
+> keyword is verified.
+
+That is why marking something NSFW is not a punishment: it routes the photo around an
+external service while keeping it in your own library workflow.
+
+The gate is re-checked *after* the provider call as well. If a decision flips to NSFW
+while an analysis is in flight, the result is discarded rather than stored.
+
+## Reading the view
+
+The tabs filter by state. Each row shows the path, the model's score, its suggestion,
+your decision, and an `✓ exif` badge once the keyword is verified on disk. A row
+without that badge has a decision the file does not yet carry.
+
+Next: [analysis](analysis.md).

docs/stages/uploads.md

@@ -0,0 +1,45 @@
+# Upload
+
+[← Documentation index](../index.md) · [Guided first pass](../first-pass.md)
+
+![Upload preflight](../images/uploads.png)
+
+**What it is for.** Sending an approved album to Immich through `immich-go`, with an
+audit trail of exactly which bytes went.
+
+**What you decide.** Which albums, and whether to proceed once the preflight has
+listed its blockers. Upload is never an automatic consequence of renaming.
+
+**What it changes.** Nothing locally. On the Immich server, assets appear. Locally a
+batch is recorded: the album, the asset ids, the redacted command, the uploader
+version, the pre-upload SHA-256 **and** the SHA-1 Immich matches on, the output log,
+and the outcome counts.
+
+**What it refuses.** Preflight blocks on: missing credentials, an unreachable server,
+a missing `immich-go`, an unresolved rename, an undecided or deferred safety
+decision, an unverified EXIF checkpoint, incomplete analysis for an SFW photo, a file
+whose bytes changed since it was checkpointed, and a partial scope you have not
+explicitly accepted. The approval is then **re-proved immediately before the uploader
+runs** — bytes edited after you approved fail with `stale_preflight` and the uploader
+never starts.
+
+## Reading the view
+
+The scope shows exactly which albums and how many photos. The command preview is the
+real command with the API key removed; the key never reaches the browser and never
+reaches a log.
+
+## Uncertain is not failed
+
+If the process dies after the server accepted files, the batch becomes
+`unknown_requires_verification` — not "failed", and **not retryable**. The server may
+already hold the photographs, and uploading again would create duplicates or
+upgrades. Verification asks Immich about the recorded SHA-1 and answers present,
+absent, or inconclusive; an inconclusive answer is resolved by you, with the evidence
+recorded.
+
+If a file's bytes change after a successful upload, it is marked
+`changed_after_upload` and you are warned that uploading again may create or upgrade
+an asset rather than doing nothing.
+
+Next: [archive](archive.md).

frontend/css/app.css

@@ -170,6 +170,20 @@ a.link:hover { text-decoration: underline; }
 .grid th, .grid td { text-align: left; padding: 6px 8px; border-bottom: 1px solid var(--border); vertical-align: top; }
 .path { font-family: ui-monospace, monospace; font-size: 0.85em; word-break: break-all; }
 
+/* Docs: prose, so it gets a reading measure rather than the full window width. */
+.doc { max-width: 72ch; }
+.doc h1 { margin-top: 0; }
+.doc h2, .doc h3 { margin-top: 1.6em; border-bottom: 1px solid var(--border); padding-bottom: 4px; }
+.doc code { font-family: ui-monospace, monospace; font-size: 0.9em; background: var(--surface-2); padding: 1px 4px; border-radius: 4px; }
+.doc pre { background: var(--surface-2); border: 1px solid var(--border); border-radius: var(--radius); padding: 12px; overflow: auto; }
+.doc pre code { background: none; padding: 0; }
+.doc table { border-collapse: collapse; width: 100%; }
+.doc th, .doc td { text-align: left; padding: 6px 8px; border-bottom: 1px solid var(--border); vertical-align: top; }
+.doc blockquote { margin: 1em 0; padding-left: 12px; border-left: 3px solid var(--border); color: var(--muted); }
+.doc img { max-width: 100%; }
+.diagram { margin: 1.5em 0; padding: 0; overflow: auto; }
+.diagram svg { max-width: 100%; height: auto; }
+
 /* Narrow screens: stack the panes so blockers and actions stay reachable. */
 @media (max-width: 720px) {
   .two-pane { grid-template-columns: 1fr; }

frontend/index.html

@@ -21,6 +21,7 @@
         <a href="#/uploads" data-nav="uploads">Upload</a>
         <a href="#/archive" data-nav="archive">Archive</a>
         <a href="#/stats" data-nav="stats">Stats</a>
+        <a href="#/docs" data-nav="docs">Docs</a>
       </nav>
     </header>
     <main id="app" aria-live="polite"><!-- views render here --></main>

frontend/js/app.js

@@ -1,5 +1,7 @@
 import { api } from "./api.js";
 import { renderArchive, setArchiveRender } from "./archive.js";
+import { renderDocs } from "./docs.js";
+import { show as showIn } from "./dom.js";
 import { navigate, onRouteChange, parseHash } from "./router.js";
 import { renderRenames, setRenamesRender } from "./renames.js";
 import { renderUploads, setUploadsRender } from "./uploads.js";
@@ -34,7 +36,7 @@ function el(tag, attrs = {}, ...children) {
 }
 
 function show(...nodes) {
-  root.replaceChildren(...nodes);
+  showIn(root, ...nodes);
 }
 
 function setActiveNav(view) {
@@ -385,6 +387,7 @@ function render() {
   else if (path === "/uploads") renderUploads(root, params);
   else if (path === "/archive") renderArchive(root, params);
   else if (path === "/stats") renderStats(root, params);
+  else if (path === "/docs") renderDocs(root, params);
   else show(errorBanner("Unknown view"));
 }
 

frontend/js/archive.js

@@ -9,7 +9,7 @@
 // is not mounted produces an instruction naming it rather than a disabled mystery,
 // and an operation whose evidence is ambiguous offers no button at all.
 import { api } from "./api.js";
-import { el, errorBanner, setActiveNav } from "./dom.js";
+import { el, errorBanner, setActiveNav, show } from "./dom.js";
 import { subscribeJob } from "./events.js";
 import { navigate } from "./router.js";
 
@@ -46,7 +46,7 @@ export async function renderArchive(root, params = {}) {
   try {
     locations = (await api.archiveLocations()).locations;
   } catch (error) {
-    root.replaceChildren(errorBanner(`Failed to load archive locations: ${error.message}`));
+    show(root, errorBanner(`Failed to load archive locations: ${error.message}`));
     return;
   }
   const location = locations.find((l) => l.id === params.location) || locations[0] || null;
@@ -61,7 +61,7 @@ export async function renderArchive(root, params = {}) {
       ),
       outcomeBanner()
     );
-    root.replaceChildren(...nodes.filter(Boolean));
+    show(root, ...nodes.filter(Boolean));
     return;
   }
 
@@ -95,7 +95,7 @@ export async function renderArchive(root, params = {}) {
     archived ? archivedSection(archived.items, locations) : null,
     restore ? restoreSection(restore, location) : null
   );
-  root.replaceChildren(...nodes.filter(Boolean));
+  show(root, ...nodes.filter(Boolean));
 }
 
 function plans(listed) {

frontend/js/docs.js

@@ -0,0 +1,263 @@
+// The documentation view (US09-01): the manuals in `docs/`, rendered in the app.
+//
+// The same markdown files are the repository's documentation and the deployment's
+// documentation. An operator who was handed a URL and an access secret has no
+// checkout in front of them, and the network the application runs on is not assumed
+// to reach a CDN — so the renderer is vendored and everything here is same-origin.
+//
+// Nothing on this page is authenticated. It is served from the static mount beside
+// the application shell, exactly like `index.html`: the troubleshooting page is
+// needed most by whoever cannot get past the access secret, and no documentation
+// file contains anything a session would protect.
+//
+// `marked` and `mermaid` are loaded lazily, on the first documentation page and the
+// first diagram. They are large, and every other view does without them.
+import { el, errorBanner, setActiveNav } from "./dom.js";
+
+const DOCS_BASE = "/docs";
+const VENDOR = "/app/js/vendor";
+const INDEX_PAGE = "index";
+// A page name comes from the hash, so it is caller input: no scheme, no traversal,
+// no absolute path. The server would refuse those too; this refuses them earlier and
+// without a request that looks like an attempt.
+const PAGE_PATTERN = /^[\w-]+(\/[\w-]+)*$/;
+
+let markedPromise;
+let mermaidPromise;
+
+function loadMarked() {
+  markedPromise ??= import(`${VENDOR}/marked.esm.js`).then((module) => module.marked);
+  return markedPromise;
+}
+
+// mermaid ships one large UMD bundle rather than a self-contained ES module, so it
+// arrives through a script element. `script-src 'self'` allows it because it is ours
+// and same-origin; nothing here relaxes that.
+function loadMermaid() {
+  mermaidPromise ??= new Promise((resolve, reject) => {
+    const script = document.createElement("script");
+    script.src = `${VENDOR}/mermaid.min.js`;
+    script.onload = () => resolve(window.mermaid);
+    script.onerror = () => reject(new Error("the diagram renderer could not be loaded"));
+    document.head.appendChild(script);
+  });
+  return mermaidPromise;
+}
+
+// ── the pure parts, unit-tested in js/tests/unit.js ──────────────────────────
+
+/** A stable, readable heading anchor. Letters and digits of any script survive. */
+export function slug(text) {
+  const cleaned = String(text)
+    .toLowerCase()
+    .trim()
+    .replace(/[^\p{L}\p{N}\s-]/gu, "")
+    .replace(/[\s-]+/g, "-")
+    .replace(/^-|-$/g, "");
+  return cleaned || "section";
+}
+
+/** Assign every heading an id, disambiguating repeats the way a reader would
+ *  expect: the first `Notes` keeps `#notes`, the second becomes `#notes-2`. */
+export function assignHeadingIds(headings) {
+  const used = new Map();
+  for (const heading of headings) {
+    const base = slug(heading.textContent);
+    const seen = (used.get(base) || 0) + 1;
+    used.set(base, seen);
+    heading.id = seen === 1 ? base : `${base}-${seen}`;
+  }
+  return headings;
+}
+
+/**
+ * Where a link inside a documentation page should go.
+ *
+ * Markdown links between documents are relative file paths, which a browser would
+ * treat as downloads that leave the application. Returns the in-app target for a
+ * link to another document or to a heading, and `null` for anything else — external
+ * links stay exactly as the author wrote them.
+ */
+export function resolveDocLink(currentPage, href) {
+  if (!href) return null;
+  if (/^[a-z][a-z\d+.-]*:/i.test(href) || href.startsWith("//")) return null;
+  if (href.startsWith("#")) return { page: currentPage, anchor: href.slice(1) };
+  const [target, anchor = ""] = href.split("#");
+  if (!/\.md$/i.test(target)) return null;
+  // Resolved against the current document, so `../guides/x.md` means what it means
+  // in the repository. The origin is a placeholder; only the path is used.
+  const resolved = new URL(target, `https://docs.invalid/${currentPage}.md`);
+  const page = decodeURIComponent(resolved.pathname).replace(/^\//, "").replace(/\.md$/i, "");
+  return PAGE_PATTERN.test(page) ? { page, anchor } : null;
+}
+
+/**
+ * Point every in-app link at its route, and leave every other link alone.
+ *
+ * The resolved page is kept on the element, so the reading order can be read back
+ * from the rendered index rather than parsed out of the markdown a second time.
+ */
+export function rewriteLinks(article, page) {
+  for (const link of article.querySelectorAll("a[href]")) {
+    const href = link.getAttribute("href");
+    const target = resolveDocLink(page, href);
+    if (target) {
+      link.setAttribute("href", docHash(target.page, target.anchor));
+      link.dataset.docPage = target.page;
+    } else if (/^https?:/i.test(href)) {
+      link.setAttribute("rel", "noreferrer noopener");
+      link.setAttribute("target", "_blank");
+    }
+  }
+  return article;
+}
+
+/** The reading order, taken from the index document itself — one list, in one
+ *  place, that is equally the index on Gitea and the navigation here. */
+export function documentIndex(indexElement) {
+  const pages = [];
+  for (const link of indexElement.querySelectorAll("a[data-doc-page]")) {
+    const page = link.dataset.docPage;
+    if (page !== INDEX_PAGE && !pages.some((entry) => entry.page === page)) {
+      pages.push({ page, title: link.textContent.trim() });
+    }
+  }
+  return pages;
+}
+
+// ── the view ─────────────────────────────────────────────────────────────────
+
+async function fetchPage(page) {
+  const response = await fetch(`${DOCS_BASE}/${page}.md`, { headers: { accept: "text/markdown" } });
+  if (!response.ok) throw new Error(`documentation page unavailable: ${response.status}`);
+  return response.text();
+}
+
+async function toArticle(markdown, page) {
+  const marked = await loadMarked();
+  const article = el("article", { class: "doc", "data-testid": "doc", "data-page": page });
+  // The only innerHTML in the application, and deliberate: rendering markdown *is*
+  // producing HTML. The input is a file from this repository, and the page's CSP
+  // (`script-src 'self'`, no `'unsafe-inline'`) means injected script and inline
+  // handlers do not run even if one ever were not.
+  article.innerHTML = marked.parse(markdown, { async: false });
+  assignHeadingIds(article.querySelectorAll("h1, h2, h3, h4, h5, h6"));
+  rewriteLinks(article, page);
+  return article;
+}
+
+function docHash(page, anchor = "") {
+  const query = new URLSearchParams(anchor ? { page, anchor } : { page });
+  return `#/docs?${query}`;
+}
+
+/** Diagrams are authored as ```mermaid blocks so the source is diffable and Gitea
+ *  renders them natively. A failure here replaces the diagram, never the page. */
+async function renderDiagrams(article) {
+  const blocks = [...article.querySelectorAll("pre > code.language-mermaid")];
+  if (!blocks.length) return;
+  let mermaid;
+  try {
+    mermaid = await loadMermaid();
+    mermaid.initialize({ startOnLoad: false, securityLevel: "strict", theme: "dark" });
+  } catch (error) {
+    blocks.forEach((block) => block.closest("pre").replaceWith(errorBanner(error.message)));
+    return;
+  }
+  for (const [index, block] of blocks.entries()) {
+    const figure = el("figure", { class: "diagram", "data-testid": "diagram" });
+    block.closest("pre").replaceWith(figure);
+    try {
+      const { svg } = await mermaid.render(`diagram-${index}-${Date.now()}`, block.textContent);
+      figure.innerHTML = svg;
+    } catch (error) {
+      figure.replaceWith(errorBanner(`Diagram could not be drawn: ${error.message}`));
+    }
+  }
+}
+
+function notFound() {
+  return el(
+    "div",
+    { class: "alert", role: "alert", "data-testid": "doc-not-found" },
+    "That documentation page does not exist. ",
+    el("a", { class: "link", href: docHash(INDEX_PAGE) }, "Back to the documentation index")
+  );
+}
+
+function sidebar(pages, current) {
+  return el(
+    "nav",
+    { class: "card", "aria-label": "Documentation" },
+    el("h2", {}, "Documentation"),
+    el(
+      "ul",
+      { class: "album-list", "data-testid": "doc-pages" },
+      el(
+        "li",
+        {},
+        el(
+          "a",
+          {
+            href: docHash(INDEX_PAGE),
+            "aria-current": current === INDEX_PAGE ? "true" : false,
+          },
+          "Index"
+        )
+      ),
+      ...pages.map(({ page, title }) =>
+        el(
+          "li",
+          {},
+          el(
+            "a",
+            {
+              href: docHash(page),
+              "data-page": page,
+              "aria-current": page === current ? "true" : false,
+            },
+            title
+          )
+        )
+      )
+    )
+  );
+}
+
+export async function renderDocs(root, params = {}) {
+  setActiveNav("docs");
+  const requested = params.page || INDEX_PAGE;
+  const page = PAGE_PATTERN.test(requested) ? requested : "";
+
+  let indexArticle;
+  try {
+    indexArticle = await toArticle(await fetchPage(INDEX_PAGE), INDEX_PAGE);
+  } catch (error) {
+    root.replaceChildren(errorBanner(`Documentation is unavailable: ${error.message}`));
+    return;
+  }
+  const pages = documentIndex(indexArticle);
+
+  let article;
+  if (!page) article = notFound();
+  else if (page === INDEX_PAGE) article = indexArticle;
+  else {
+    try {
+      article = await toArticle(await fetchPage(page), page);
+    } catch {
+      article = notFound();
+    }
+  }
+
+  root.replaceChildren(el("div", { class: "two-pane" }, sidebar(pages, page), article));
+  await renderDiagrams(article);
+  scrollToAnchor(params.anchor);
+}
+
+// A documentation anchor cannot live in the hash — the hash is the route — so it
+// travels as a parameter and is applied after the page renders.
+function scrollToAnchor(anchor) {
+  if (!anchor) return;
+  const target = document.getElementById(anchor);
+  if (target) target.scrollIntoView({ block: "start" });
+}

frontend/js/dom.js

@@ -21,6 +21,19 @@ export function errorBanner(message) {
   return el("div", { class: "alert", role: "alert" }, message);
 }
 
+/**
+ * Replace a container's contents, dropping the absent ones.
+ *
+ * `el` already ignores null children, but `replaceChildren` does not: it stringifies
+ * them, so an optional node that is not there renders the word "null" on the page.
+ * Every view builds optional nodes — a banner only while a job runs, a conflict only
+ * after a 409 — so the filter belongs here rather than in each caller. It was missing
+ * from one of them, and a documentation screenshot is where that turned up (US09-04).
+ */
+export function show(root, ...nodes) {
+  root.replaceChildren(...nodes.flat().filter((node) => node != null && node !== false));
+}
+
 export function setActiveNav(view) {
   document.querySelectorAll("nav a[data-nav]").forEach((a) => {
     if (a.dataset.nav === view) a.setAttribute("aria-current", "page");

frontend/js/renames.js

@@ -5,7 +5,7 @@
 // recovery classifications all come from the server; the view only shows them and
 // refuses to offer an action the server would reject.
 import { api } from "./api.js";
-import { el, errorBanner, setActiveNav } from "./dom.js";
+import { el, errorBanner, setActiveNav, show } from "./dom.js";
 
 // What the last confirm did, for this tab only. Deliberately not persisted: after a
 // reload the page must show what the journal says, not what this page remembers.
@@ -24,7 +24,7 @@ export async function renderRenames(root, params = {}) {
   try {
     [plans, recovery] = await Promise.all([api.listPlans(), api.renameRecovery()]);
   } catch (error) {
-    root.replaceChildren(errorBanner(`Failed to load renames: ${error.message}`));
+    show(root, errorBanner(`Failed to load renames: ${error.message}`));
     return;
   }
 
@@ -34,13 +34,13 @@ export async function renderRenames(root, params = {}) {
     try {
       plan = await api.getPlan(selectedId);
     } catch (error) {
-      root.replaceChildren(errorBanner(`Failed to load plan: ${error.message}`));
+      show(root, errorBanner(`Failed to load plan: ${error.message}`));
       return;
     }
   }
 
   const blocked = recovery.blocks_mutation;
-  root.replaceChildren(
+  show(root,
     el("h1", {}, "Renames"),
     recoveryPanel(recovery),
     el(

frontend/js/tests/unit.js

@@ -7,6 +7,7 @@ import { createStore } from "../store.js";
 import { parseHash, navigate } from "../router.js";
 import { api, cancellable } from "../api.js";
 import { subscribeJob } from "../events.js";
+import { assignHeadingIds, documentIndex, resolveDocLink, rewriteLinks, slug } from "../docs.js";
 
 const cases = [];
 function ok(name, cond) {
@@ -142,6 +143,62 @@ async function run() {
     window.EventSource = realES;
   }
 
+  // ── documentation view (US09-01) ─────────────────────────────────────────
+  {
+    ok("slug lowercases and dashes a heading", slug("Key Flows") === "key-flows");
+    ok(
+      "slug drops punctuation but keeps words",
+      slug("What it *will not* do:") === "what-it-will-not-do"
+    );
+    ok("slug keeps non-ASCII letters", slug("Größe & Gewicht") === "größe-gewicht");
+    ok("slug never yields an empty anchor", slug("!!!") === "section");
+
+    const doc = document.createElement("div");
+    doc.innerHTML = "<h2>Notes</h2><h3>Notes</h3><h2>Notes</h2>";
+    const ids = [...assignHeadingIds(doc.querySelectorAll("h2, h3"))].map((h) => h.id);
+    ok("repeated headings get distinct anchors", ids.join(",") === "notes,notes-2,notes-3");
+
+    ok(
+      "a sibling document link becomes an in-app route",
+      resolveDocLink("index", "overview.md")?.page === "overview"
+    );
+    const nested = resolveDocLink("guides/install", "../overview.md#running-it");
+    ok("a relative link resolves against the current page", nested?.page === "overview");
+    ok("a link's anchor survives the rewrite", nested?.anchor === "running-it");
+    ok(
+      "a bare anchor stays on the current page",
+      resolveDocLink("overview", "#the-workflow")?.page === "overview"
+    );
+    ok("an external link is left alone", resolveDocLink("index", "https://example.test/x") === null);
+    ok("a non-markdown relative link is left alone", resolveDocLink("index", "images/a.png") === null);
+    // A climb cannot leave the documentation tree: it is clamped at the root, so the
+    // page it names is still fetched from under /docs and simply does not exist.
+    ok(
+      "a link that climbs above the docs root is clamped",
+      resolveDocLink("index", "../../etc/passwd.md")?.page === "etc/passwd"
+    );
+    ok(
+      "a page name that is not a page name is refused",
+      resolveDocLink("index", "..%2f..%2fetc%2fpasswd.md") === null
+    );
+
+    const index = document.createElement("div");
+    index.innerHTML =
+      '<a href="overview.md">Overview</a><a href="overview.md">again</a>' +
+      '<a href="index.md">itself</a><a href="https://example.test">out</a>';
+    const listed = documentIndex(rewriteLinks(index, "index"));
+    ok(
+      "an external link is marked safe to open away from the app",
+      index.querySelector('a[href^="https"]').rel === "noreferrer noopener"
+    );
+    ok(
+      "an in-app link points at the docs route",
+      index.querySelector("a").getAttribute("href") === "#/docs?page=overview"
+    );
+    ok("the index lists each page once, in order", listed.length === 1);
+    ok("the index takes its titles from the link text", listed[0].title === "Overview");
+  }
+
   await tick();
   const failed = cases.filter((c) => !c.ok);
   window.__RESULTS__ = { passed: cases.length - failed.length, failed: failed.length, cases };

frontend/js/uploads.js

@@ -8,7 +8,7 @@
 // preview arrives redacted — so nothing in this view may reconstruct, store, or
 // route a secret.
 import { api } from "./api.js";
-import { el, errorBanner, setActiveNav } from "./dom.js";
+import { el, errorBanner, setActiveNav, show } from "./dom.js";
 import { subscribeJob } from "./events.js";
 import { navigate } from "./router.js";
 
@@ -45,7 +45,7 @@ export async function renderUploads(root, params = {}) {
       api.listUploadBatches(),
     ]);
   } catch (error) {
-    root.replaceChildren(errorBanner(`Failed to load uploads: ${error.message}`));
+    show(root, errorBanner(`Failed to load uploads: ${error.message}`));
     return;
   }
 
@@ -62,12 +62,12 @@ export async function renderUploads(root, params = {}) {
       batch = detail;
       history = verifications.verifications;
     } catch (error) {
-      root.replaceChildren(errorBanner(`Failed to load upload batch: ${error.message}`));
+      show(root, errorBanner(`Failed to load upload batch: ${error.message}`));
       return;
     }
   }
 
-  root.replaceChildren(
+  show(root,
     ...[
       el("h1", {}, "Upload"),
       configurationCard(preflight),

frontend/js/vendor/VERSIONS.json

@@ -0,0 +1,23 @@
+{
+  "_comment": "Vendored browser libraries (US09-01). Committed rather than fetched: the application is deployed to a network whose outbound access is not assumed, and `default-src 'self'` forbids a CDN. Checksums are asserted by tests/integration/test_documentation.py, so replacing a file without recording it here fails the suite. Update by downloading the pinned URL and recording the new version and sha256 in the same commit.",
+  "libraries": [
+    {
+      "file": "marked.esm.js",
+      "name": "marked",
+      "version": "18.0.10",
+      "license": "MIT",
+      "url": "https://cdn.jsdelivr.net/npm/marked@18.0.10/lib/marked.esm.js",
+      "sha256": "4cf47dfebb7f614a08fc0a579ab0fe407ff0ed2b717bf953040c85b2f493a4f0",
+      "why": "Markdown to HTML for the documentation view. An ES module with no dependencies, imported lazily by js/docs.js."
+    },
+    {
+      "file": "mermaid.min.js",
+      "name": "mermaid",
+      "version": "11.17.0",
+      "license": "MIT",
+      "url": "https://cdn.jsdelivr.net/npm/mermaid@11.17.0/dist/mermaid.min.js",
+      "sha256": "8d8e0eec56d3a83b4b3c87f42050845546dee93ebe1875d2117c12e6947c0cb3",
+      "why": "Renders ```mermaid blocks so diagrams are diffable source that Gitea also renders. The single-file UMD build rather than the ES module entry, whose ~40 lazy chunks would each need vendoring and pinning."
+    }
+  ]
+}

frontend/js/views.js

@@ -3,7 +3,7 @@
 // HTML. Mutating actions are disabled while a job holds the library_write lock and
 // say why (concept §shared interaction rules: read-only browsing stays available).
 import { api } from "./api.js";
-import { el, errorBanner, setActiveNav } from "./dom.js";
+import { el, errorBanner, setActiveNav, show } from "./dom.js";
 import { navigate } from "./router.js";
 import { subscribeJob } from "./events.js";
 
@@ -26,7 +26,7 @@ export async function renderWorkflow(root) {
   try {
     data = await api.workflow();
   } catch (error) {
-    root.replaceChildren(errorBanner(`Failed to load workflow: ${error.message}`));
+    show(root, errorBanner(`Failed to load workflow: ${error.message}`));
     return;
   }
   const active = data.active_job;
@@ -67,7 +67,7 @@ export async function renderWorkflow(root) {
       )
     );
   });
-  root.replaceChildren(
+  show(root,
     el("h1", {}, "Workflow"),
     jobBanner(active),
     el("div", { class: "stepper" }, ...cards)
@@ -105,7 +105,7 @@ export async function renderSafety(root, params) {
   try {
     data = await api.safetyQueue({ state });
   } catch (error) {
-    root.replaceChildren(errorBanner(`Failed to load safety queue: ${error.message}`));
+    show(root, errorBanner(`Failed to load safety queue: ${error.message}`));
     return;
   }
 
@@ -149,7 +149,7 @@ export async function renderSafety(root, params) {
     )
   );
 
-  root.replaceChildren(
+  show(root,
     el("h1", {}, "Safety review"),
     tabs,
     el(
@@ -197,7 +197,7 @@ export async function renderLibrary(root, params) {
   try {
     data = await api.libraryAssets({ q, offset, limit, sort: params.sort || "path" });
   } catch (error) {
-    root.replaceChildren(errorBanner(`Failed to load library: ${error.message}`));
+    show(root, errorBanner(`Failed to load library: ${error.message}`));
     return;
   }
 
@@ -220,7 +220,7 @@ export async function renderLibrary(root, params) {
     )
   );
 
-  root.replaceChildren(
+  show(root,
     el("h1", {}, "Library"),
     el("div", { class: "toolbar" }, search, el("span", { class: "muted", "data-testid": "library-total" }, `${data.total} photos`)),
     data.rows.length ? el("div", { class: "cluster-grid" }, ...cards) : el("p", { class: "muted" }, "No matching photos."),
@@ -235,7 +235,7 @@ export async function renderAnalyze(root) {
   try {
     [counts, workflow] = await Promise.all([api.analysisCounts(), api.workflow()]);
   } catch (error) {
-    root.replaceChildren(errorBanner(`Failed to load analysis: ${error.message}`));
+    show(root, errorBanner(`Failed to load analysis: ${error.message}`));
     return;
   }
   const active = workflow.active_job;
@@ -269,7 +269,7 @@ export async function renderAnalyze(root) {
     "Analyze eligible SFW assets"
   );
 
-  root.replaceChildren(
+  show(root,
     el("h1", {}, "Analyze"),
     jobBanner(active),
     el(
@@ -292,10 +292,10 @@ export async function renderStats(root) {
   try {
     data = await api.libraryStats();
   } catch (error) {
-    root.replaceChildren(errorBanner(`Failed to load stats: ${error.message}`));
+    show(root, errorBanner(`Failed to load stats: ${error.message}`));
     return;
   }
-  root.replaceChildren(
+  show(root,
     el("h1", {}, "Stats"),
     el("div", { class: "counts-grid", "data-testid": "stats-status" }, ...Object.entries(data.status).map(([k, v]) => stat(k, v))),
     facetBlock("Top tags", data.top_tags),
@@ -338,7 +338,7 @@ export async function renderAlbums(root, params = {}) {
       api.renameRecovery(),
     ]);
   } catch (error) {
-    root.replaceChildren(errorBanner(`Failed to load albums: ${error.message}`));
+    show(root, errorBanner(`Failed to load albums: ${error.message}`));
     return;
   }
 
@@ -385,7 +385,7 @@ export async function renderAlbums(root, params = {}) {
       )
     : el("p", { class: "muted" }, "No albums with evidence yet.");
 
-  root.replaceChildren(
+  show(root,
     el("h1", {}, "Albums"),
     renameBlocked
       ? el(

photo_pipeline/api/app.py

@@ -53,6 +53,7 @@ from photo_pipeline.services.thumbnails import ThumbnailService
 from photo_pipeline.services.upload_batches import UploadBatchService
 
 FRONTEND_DIR = Path(__file__).resolve().parents[2] / "frontend"
+DOCS_DIR = Path(__file__).resolve().parents[2] / "docs"
 
 log = logging.getLogger(__name__)
 
@@ -151,4 +152,10 @@ def create_app(config: Config | None = None) -> FastAPI:
     # Static single-page app (hash-routed). Mounted last so /api/v1 wins.
     if FRONTEND_DIR.is_dir():
         app.mount("/app", StaticFiles(directory=FRONTEND_DIR, html=True), name="app")
+    # The manuals, as their own markdown files (US09-01). Unauthenticated for the
+    # same reason the application shell is: whoever cannot get past the access
+    # secret is exactly who needs the troubleshooting page, and no document holds
+    # anything a session would protect.
+    if DOCS_DIR.is_dir():
+        app.mount("/docs", StaticFiles(directory=DOCS_DIR), name="docs")
     return app

photo_pipeline/api/security.py

@@ -57,9 +57,21 @@ LOOPBACK_HOSTS = frozenset({"127.0.0.1", "localhost", "::1", "[::1]"})
 # backup a careful operator takes first, and its retention (US07-07).
 MUTATION_EXEMPT_PATHS = frozenset({f"{API_PREFIX}/backups", f"{API_PREFIX}/backups/prune"})
 
-# Applied to every response. No inline script/style is used by the frontend, so the
-# policy can stay strict; `frame-ancestors 'none'` and CORP keep other pages from
+# Applied to every response. `frame-ancestors 'none'` and CORP keep other pages from
 # embedding the app or its thumbnails.
+#
+# `script-src 'self'` is the boundary that matters and it is unchanged: no
+# `'unsafe-eval'`, no `'unsafe-inline'`, so nothing injected into the DOM can execute.
+# Whether the vendored diagram renderer needed `'unsafe-eval'` was measured rather
+# than assumed — mermaid's bundle contains no `eval(` and no `new Function`, and it
+# renders under this exact policy without a single script-src violation.
+#
+# `style-src` does gain `'unsafe-inline'` (US09-01): mermaid styles the SVG it builds
+# with an injected `<style>` element and `style=` attributes, and a diagram's CSS
+# cannot be hashed in advance. The concession is bounded by the directives around it
+# — with script execution still refused and `img-src`, `connect-src`, and `font-src`
+# all `'self'`, the CSS exfiltration channels stay closed and what is left is
+# defacement of a page its own operator is already looking at.
 DEFAULT_HEADERS = {
     "x-content-type-options": "nosniff",
     "x-frame-options": "DENY",
@@ -67,8 +79,9 @@ DEFAULT_HEADERS = {
     "cross-origin-resource-policy": "same-origin",
     "cross-origin-opener-policy": "same-origin",
     "content-security-policy": (
-        "default-src 'self'; img-src 'self' data:; style-src 'self'; script-src 'self'; "
-        "connect-src 'self'; frame-ancestors 'none'; base-uri 'none'; form-action 'none'"
+        "default-src 'self'; img-src 'self' data:; style-src 'self' 'unsafe-inline'; "
+        "script-src 'self'; connect-src 'self'; font-src 'self'; "
+        "frame-ancestors 'none'; base-uri 'none'; form-action 'none'"
     ),
 }
 

tests/e2e/test_docs_ui.py

@@ -0,0 +1,149 @@
+"""US09-01: the manuals, in the browser, under the application's real policy.
+
+Everything here runs against a real ``photo_pipeline serve`` process serving the
+committed ``docs/`` tree and the vendored renderer — no fixture markdown, no stubbed
+fetch. What that buys is the assertion the story actually cares about: the pages
+render, the links between them work, a diagram becomes a diagram, and the console
+stays empty, including of CSP violations.
+
+The offline contract — reachability, dead links, pinned checksums — is
+``tests/integration/test_documentation.py``.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+
+from tests.e2e._pipeline_harness import Server, seed_library
+
+
+@pytest.fixture(scope="module")
+def server(tmp_path_factory):
+    seeded = seed_library(tmp_path_factory.mktemp("docs"), {"a": 1}, {})
+    running = Server(seeded).start()
+    try:
+        yield running
+    finally:
+        running.stop()
+
+
+@pytest.fixture
+def quiet(page):
+    """Any console error, page error, or failed request fails the test that caused
+    it. A CSP violation arrives as a console error, which is the point."""
+    problems: list[str] = []
+    page.on("console", lambda m: problems.append(m.text) if m.type == "error" else None)
+    page.on("pageerror", lambda error: problems.append(str(error)))
+    page.on("requestfailed", lambda request: problems.append(f"failed request: {request.url}"))
+    yield problems
+
+
+def test_the_documentation_opens_from_the_navigation(page, server, quiet):
+    page.goto(f"{server.base}/app/#/workflow")
+    page.locator('nav a[data-nav="docs"]').click()
+
+    page.get_by_test_id("doc").wait_for()
+    assert page.get_by_test_id("doc").get_attribute("data-page") == "index"
+    # The sidebar is the index's own reading order, not a second list to maintain.
+    assert page.get_by_test_id("doc-pages").get_by_role("link", name="Overview").is_visible()
+    assert quiet == []
+
+
+def test_a_link_between_documents_stays_inside_the_application(page, server, quiet):
+    page.goto(f"{server.base}/app/#/docs")
+    page.get_by_test_id("doc").wait_for()
+    page.get_by_test_id("doc").get_by_role("link", name="Overview").click()
+
+    page.wait_for_selector('[data-testid="doc"][data-page="overview"]')
+    assert "#/docs?page=overview" in page.url, "a relative .md link must not leave the app"
+    # And back again, by the link the document itself carries.
+    page.get_by_test_id("doc").get_by_role("link", name="← Documentation index").click()
+    page.wait_for_selector('[data-testid="doc"][data-page="index"]')
+    assert quiet == []
+
+
+def test_a_deep_link_to_a_heading_lands_on_that_heading(page, server, quiet):
+    page.goto(f"{server.base}/app/#/docs?page=overview&anchor=the-workflow")
+    heading = page.locator("#the-workflow")
+    heading.wait_for()
+
+    assert heading.inner_text().strip() == "The workflow"
+    assert heading.evaluate("node => node.getBoundingClientRect().top < window.innerHeight")
+    assert quiet == []
+
+
+def test_a_mermaid_block_becomes_a_diagram_under_the_unchanged_script_policy(page, server, quiet):
+    page.goto(f"{server.base}/app/#/docs?page=overview")
+    diagram = page.get_by_test_id("diagram").first
+    diagram.wait_for()
+
+    # A real drawing, not the source text and not an error node.
+    assert diagram.locator("svg").count() == 1
+    assert diagram.evaluate("node => node.querySelector('svg').getBBox().width") > 100
+    assert page.locator("pre code.language-mermaid").count() == 0
+    assert quiet == [], "rendering a diagram must not violate the policy"
+
+    policy = page.evaluate(
+        "async () => (await fetch('/app/')).headers.get('content-security-policy')"
+    )
+    assert "script-src 'self';" in policy
+    assert "unsafe-eval" not in policy
+
+
+def test_every_diagram_in_the_architecture_overview_draws(page, server, quiet):
+    """Five diagrams, three of them state machines (US09-03). A mermaid block with a
+    syntax error renders an error node instead of throwing, so a page that merely
+    loaded proves nothing — count the drawings and read the source for the states."""
+    source = (Path(__file__).resolve().parents[2] / "docs" / "architecture.md").read_text()
+    expected = source.count("```mermaid")
+    assert expected >= 5, "the overview lost its diagrams"
+
+    page.goto(f"{server.base}/app/#/docs?page=architecture")
+    page.get_by_test_id("diagram").first.wait_for()
+    page.wait_for_function(
+        "count => document.querySelectorAll('[data-testid=\"diagram\"] svg').length === count",
+        arg=expected,
+    )
+
+    drawn = page.locator('[data-testid="diagram"] svg')
+    assert drawn.count() == expected
+    for index in range(expected):
+        diagram = drawn.nth(index)
+        # Labels may be <text> or HTML inside a <foreignObject> depending on the
+        # diagram type, so ask for the rendered text rather than a specific element.
+        labels = diagram.evaluate("node => node.textContent.trim().length")
+        assert labels > 0, f"diagram {index} drew no labels"
+        assert diagram.locator(".error-icon, .error-text").count() == 0, f"diagram {index} errored"
+    assert page.locator("pre code.language-mermaid").count() == 0
+    assert quiet == []
+
+
+def test_an_unknown_page_says_so_without_naming_a_path(page, server, quiet):
+    page.goto(f"{server.base}/app/#/docs?page=no-such-manual")
+    message = page.get_by_test_id("doc-not-found")
+    message.wait_for()
+
+    text = message.inner_text()
+    assert "does not exist" in text
+    assert "/" not in text.replace("Back to the documentation index", ""), text
+    message.get_by_role("link").click()
+    page.wait_for_selector('[data-testid="doc"][data-page="index"]')
+    # The missing page is a 404 and the browser says so; nothing else may go wrong,
+    # and in particular the view must not throw on the way to its own message.
+    assert all("404" in problem for problem in quiet), quiet
+
+
+def test_the_documentation_is_readable_without_a_session(page, server, quiet):
+    """The troubleshooting page is needed most by whoever is locked out."""
+    page.goto(f"{server.base}/app/#/docs")
+    page.get_by_test_id("doc").wait_for()
+    unauthenticated = page.evaluate(
+        """async () => {
+             const response = await fetch('/docs/index.md', { credentials: 'omit' });
+             return { status: response.status, length: (await response.text()).length };
+           }"""
+    )
+    assert unauthenticated["status"] == 200
+    assert unauthenticated["length"] > 100

tests/e2e/test_user_manual_screenshots.py

@@ -0,0 +1,144 @@
+"""US09-04: the user manual's screenshots, produced from the running application.
+
+A screenshot nobody can regenerate is a screenshot that silently stops being true.
+So every image in the manual is captured here, from a real server and a real worker
+driving a temporary fixture library, and never pasted in by hand.
+
+Regenerate the committed images with one command:
+
+    PHOTO_PIPELINE_WRITE_SCREENSHOTS=1 work_item/scripts/python -m pytest \
+        tests/e2e/test_user_manual_screenshots.py -q
+
+Without that variable the capture still runs on every suite — the generator has to
+keep working, and a view that stops rendering must fail here rather than in a
+reader's browser — but the images go to a temporary directory. Regenerating on every
+run would leave the working tree permanently dirty, because PNG output is not
+byte-stable.
+"""
+
+from __future__ import annotations
+
+import os
+import re
+from contextlib import closing
+from pathlib import Path
+
+import pytest
+
+from tests.conftest import session_client
+from tests.e2e._pipeline_harness import (
+    Server,
+    seed_album,
+    start_worker,
+    wait_until,
+)
+
+REPO = Path(__file__).resolve().parents[2]
+DOCS = REPO / "docs"
+IMAGES = DOCS / "images"
+ALBUM = "rome"
+VIEWPORT = {"width": 1280, "height": 900}
+
+# One per stage page of the manual: the route to visit, and the element whose
+# presence means the view has actually finished rendering.
+SHOTS = (
+    ("workflow", "#/workflow", "stage-safety"),
+    ("inventory", "#/inventory", "asset-row"),
+    ("duplicates", "#/duplicates", None),
+    ("safety", "#/safety", None),
+    ("analysis", "#/analyze", "analyze-counts"),
+    ("albums", f"#/albums?album={ALBUM}", "suggested-name"),
+    ("renames", "#/renames", None),
+    ("uploads", "#/uploads", "upload-scope"),
+    ("archive", "#/archive", "archive-locations"),
+    ("statistics", "#/stats", None),
+)
+
+
+def writing() -> bool:
+    return os.environ.get("PHOTO_PIPELINE_WRITE_SCREENSHOTS") == "1"
+
+
+@pytest.fixture(scope="module")
+def stack(tmp_path_factory):
+    """A library in the state the manual describes: one analysed album, a duplicate
+    to review, an archive destination, and a worker that claims jobs."""
+    tmp_path = tmp_path_factory.mktemp("manual")
+    seeded = seed_album(tmp_path, ALBUM, ("forum.jpg", "colosseum.jpg"))
+    worker = start_worker(seeded, fake_vision_log=tmp_path / "vision.log")
+    server = Server(seeded).start()
+    try:
+        _prepare(server.base, seeded)
+        yield server
+    finally:
+        server.stop()
+        worker.terminate()
+        worker.wait(timeout=10)
+
+
+def _prepare(base: str, seeded) -> None:
+    """Everything the views need, established over the public API — the same calls a
+    person would make, so the screenshots show reachable states."""
+    with closing(session_client(base, timeout=30)) as client:
+        client.post("/api/v1/duplicates/detect").raise_for_status()
+        client.post("/api/v1/albums/proposals", json={}).raise_for_status()
+        destination = seeded.data / "archive"
+        destination.mkdir(exist_ok=True)
+        client.post(
+            "/api/v1/archive-locations",
+            json={"name": "external disk", "root": str(destination)},
+        ).raise_for_status()
+        wait_until(lambda: client.get("/api/v1/workflow").status_code == 200)
+
+
+def _capture(page, server, target: Path) -> list[str]:
+    target.mkdir(parents=True, exist_ok=True)
+    page.set_viewport_size(VIEWPORT)
+    written = []
+    for name, route, ready in SHOTS:
+        page.goto(f"{server.base}/app/{route}")
+        if ready:
+            page.get_by_test_id(ready).first.wait_for(timeout=30_000)
+        else:
+            page.locator("main h1").first.wait_for(timeout=30_000)
+        page.screenshot(path=str(target / f"{name}.png"))
+        written.append(name)
+    return written
+
+
+def test_the_generator_produces_every_screenshot_the_manual_references(page, stack, tmp_path):
+    destination = IMAGES if writing() else tmp_path / "images"
+    written = _capture(page, stack, destination)
+
+    assert sorted(written) == sorted(name for name, _, _ in SHOTS)
+    for name in written:
+        produced = destination / f"{name}.png"
+        assert produced.stat().st_size > 5_000, f"{name}.png is too small to be a view"
+
+    referenced = set(re.findall(r"images/([a-z-]+)\.png", "\n".join(
+        path.read_text() for path in DOCS.rglob("*.md")
+    )))
+    assert referenced <= set(written), f"the manual references images nobody generates: {referenced - set(written)}"
+
+
+def test_no_screenshot_shows_a_real_path_or_a_secret(page, stack, tmp_path):
+    """The fixture library is synthetic and lives in a temporary directory, so the
+    pixels cannot carry someone's photographs — but the view can still print a path,
+    and that path must be the fixture's, never the operator's."""
+    with closing(session_client(stack.base, timeout=30)) as client:
+        rendered = client.get("/api/v1/inventory/assets", params={"limit": 200}).json()["items"]
+    paths = [item["current_path"] for item in rendered if item["current_path"]]
+    assert paths, "nothing was rendered, so nothing was proven"
+    assert all("/manual" in path or "pytest" in path or "/tmp" in path or "/var" in path for path in paths), paths
+    assert all(ALBUM in path or "images" in path for path in paths)
+
+
+def test_every_committed_screenshot_is_referenced_by_a_page():
+    """An image nobody shows is an image nobody updates."""
+    if not IMAGES.is_dir():
+        pytest.skip("no screenshots have been generated into the repository yet")
+    text = "\n".join(path.read_text() for path in DOCS.rglob("*.md"))
+    orphans = sorted(
+        image.name for image in IMAGES.glob("*.png") if f"images/{image.name}" not in text
+    )
+    assert orphans == [], f"committed but unreferenced: {orphans}"

tests/integration/test_architecture_overview.py

@@ -0,0 +1,164 @@
+"""US09-03: the architecture overview, checked against the architecture.
+
+An architecture document is the one that rots most quietly: nothing breaks when it
+describes a module that was renamed two epics ago, it just quietly misleads the next
+person. So the parts of it that the code also knows — module names, state machines,
+table names, the modules an invariant is claimed to live in — are compared with the
+code, and a missing one fails the suite.
+
+The diagrams' rendering is proven in ``tests/e2e/test_docs_ui.py``.
+"""
+
+from __future__ import annotations
+
+import re
+from pathlib import Path
+
+import photo_pipeline.models  # noqa: F401  (registers every table on Base.metadata)
+from photo_pipeline.db import Base
+from photo_pipeline.services import jobs, rename_journal, upload_batches
+
+REPO = Path(__file__).resolve().parents[2]
+PACKAGE = REPO / "photo_pipeline"
+OVERVIEW = REPO / "docs" / "architecture.md"
+TEXT = OVERVIEW.read_text()
+
+# Names the map does not owe the reader individually: the package markers, the CLI
+# entry point, and the two modules that exist to be small and obvious.
+UNMAPPED = {"__init__", "__main__", "logging"}
+
+
+def modules() -> set[str]:
+    """Every module and package under photo_pipeline, by the name it is imported as."""
+    names = set()
+    for path in PACKAGE.rglob("*.py"):
+        relative = path.relative_to(PACKAGE)
+        names.add(relative.parts[0] if len(relative.parts) > 1 else relative.stem)
+    return {name.removesuffix(".py") for name in names} - UNMAPPED
+
+
+def states(container: type) -> set[str]:
+    return {
+        value
+        for name, value in vars(container).items()
+        if name.isupper() and isinstance(value, str)
+    }
+
+
+# ── the module map ───────────────────────────────────────────────────────────
+
+
+def test_every_module_appears_in_the_map():
+    """A service nobody documented is a service the next person re-implements."""
+    missing = sorted(name for name in modules() if name not in TEXT)
+    assert missing == [], f"absent from the architecture overview: {missing}"
+
+
+def test_every_service_is_named_individually():
+    """The package table says what `services/` is for; this is the list that actually
+    drifts, because a new service is added roughly every story."""
+    services = {path.stem for path in (PACKAGE / "services").glob("*.py")} - UNMAPPED
+    missing = sorted(name for name in services if not re.search(rf"\b{name}\b", TEXT))
+    assert missing == [], f"services missing from the overview: {missing}"
+
+
+def test_the_map_names_no_module_that_does_not_exist():
+    """Every `services/<name>` or backticked module path in the document resolves."""
+    referenced = set(re.findall(r"`(?:photo_pipeline/)?([a-z_]+)/([a-z_]+)\.py`", TEXT))
+    referenced |= {("", name) for name in re.findall(r"`([a-z_]+)\.py`", TEXT)}
+    missing = [
+        f"{package}/{module}.py" if package else f"{module}.py"
+        for package, module in referenced
+        if not (PACKAGE / package / f"{module}.py").is_file()
+    ]
+    assert missing == [], f"documented but absent from the source: {missing}"
+
+
+# ── the state machines ───────────────────────────────────────────────────────
+
+
+def test_every_job_state_is_documented():
+    missing = sorted(state for state in states(jobs.JobState) if state not in TEXT)
+    assert missing == [], f"job states missing from the overview: {missing}"
+
+
+def test_every_rename_journal_state_is_documented():
+    missing = sorted(state for state in states(rename_journal.JournalState) if state not in TEXT)
+    assert missing == [], f"journal states missing from the overview: {missing}"
+
+
+def test_every_upload_batch_state_is_documented():
+    missing = sorted(state for state in states(upload_batches.BatchState) if state not in TEXT)
+    assert missing == [], f"batch states missing from the overview: {missing}"
+
+
+def test_the_unsafe_journal_states_are_named_as_the_ones_that_block():
+    """The reason an unrelated mutation is refused has to be findable."""
+    for state in rename_journal.UNSAFE_STATES:
+        assert state in TEXT
+    assert "rename_recovery_required" in TEXT
+
+
+def test_an_uncertain_upload_is_documented_as_not_retryable():
+    assert upload_batches.BatchState.UNKNOWN not in upload_batches.RUNNABLE_STATES
+    assert "not** restartable" in TEXT or "not restartable" in TEXT
+
+
+# ── the data model ───────────────────────────────────────────────────────────
+
+
+def test_every_table_is_listed():
+    missing = sorted(name for name in Base.metadata.tables if name not in TEXT)
+    assert missing == [], f"tables missing from the overview: {missing}"
+
+
+def test_the_document_lists_no_table_that_does_not_exist():
+    listed = set(re.findall(r"`([a-z_]+)`", TEXT))
+    plausible = {name for name in listed if name.endswith("s") and "_" in name}
+    invented = sorted(
+        name
+        for name in plausible
+        if name not in Base.metadata.tables
+        and not (PACKAGE / "services" / f"{name}.py").is_file()
+        and name not in {"library_roots", "trusted_proxies", "allowed_hosts", "asset_paths"}
+    )
+    assert invented == [], f"looks like a table but is not one: {invented}"
+
+
+# ── the invariants ───────────────────────────────────────────────────────────
+
+
+def test_each_invariant_points_at_a_module_that_enforces_it():
+    """The point of the table is to answer 'where do I look'. A wrong answer there
+    costs more than no answer."""
+    claims = {
+        "path_policy.is_excluded": PACKAGE / "path_policy.py",
+        "path_policy.resolve_in_roots": PACKAGE / "path_policy.py",
+        "services/app_lock.py": PACKAGE / "services" / "app_lock.py",
+        "services/exif_checkpoint.py": PACKAGE / "services" / "exif_checkpoint.py",
+        "services/archive_transfer.py": PACKAGE / "services" / "archive_transfer.py",
+        "api/security.py": PACKAGE / "api" / "security.py",
+        "imaging.py": PACKAGE / "imaging.py",
+    }
+    for claim, path in claims.items():
+        assert claim in TEXT, f"the invariant table does not mention {claim}"
+        assert path.is_file(), f"{claim} does not exist"
+        function = claim.rpartition(".")[2] if "/" not in claim else ""
+        if function and function != "py":
+            assert f"def {function}" in path.read_text(), f"{claim} is not defined there"
+
+
+def test_the_lock_order_matches_the_ranks_in_the_code():
+    from photo_pipeline.jobs import locks
+
+    order = [name for name, _ in sorted(locks.LOCK_RANK.items(), key=lambda item: item[1])]
+    assert order[0].startswith("library"), "the broadest lock is no longer the library"
+    assert "library → stage/job → album/folder → asset" in TEXT
+
+
+def test_the_frozen_donor_archive_is_described_as_provenance_not_a_dependency():
+    """That production never imports the frozen sources is proven by
+    ``tests/unit/test_legacy_archive.py`` — which also forbids any other test from
+    naming that directory, so this one checks the claim by its consequence."""
+    assert "must not import" in TEXT
+    assert "provenance and rollback evidence" in TEXT

tests/integration/test_documentation.py

@@ -0,0 +1,179 @@
+"""US09-01: the documentation the application serves, checked without a browser.
+
+What is checkable offline is everything that makes the manuals *navigable* rather
+than merely present: every page reachable, every internal link and anchor landing
+somewhere real, the vendored renderer being the file that was pinned, and the
+application actually serving `docs/` in both the working copy and the image.
+
+The rendering itself — marked, mermaid, anchors, link rewriting — is proven in a
+real browser by ``tests/e2e/test_docs_ui.py``.
+"""
+
+from __future__ import annotations
+
+import hashlib
+import json
+import re
+from pathlib import Path
+
+from starlette.testclient import TestClient
+
+from photo_pipeline.api.app import create_app
+from photo_pipeline.api.security import DEFAULT_HEADERS
+from photo_pipeline.config import Config
+
+REPO = Path(__file__).resolve().parents[2]
+DOCS = REPO / "docs"
+VENDOR = REPO / "frontend" / "js" / "vendor"
+INDEX = DOCS / "index.md"
+
+MARKDOWN_LINK = re.compile(r"\[[^\]]*\]\(([^)\s]+)\)")
+HEADING = re.compile(r"^#{1,6}\s+(.+?)\s*$", re.MULTILINE)
+FENCE = re.compile(r"^```.*?^```", re.MULTILINE | re.DOTALL)
+
+
+def pages() -> list[Path]:
+    return sorted(DOCS.rglob("*.md"))
+
+
+def body(path: Path) -> str:
+    """A document without its fenced code, so an example link in a shell snippet is
+    not mistaken for a link the reader can follow."""
+    return FENCE.sub("", path.read_text())
+
+
+def slug(text: str) -> str:
+    """The heading-anchor rule, mirroring ``frontend/js/docs.js``.
+
+    Deliberately duplicated: this check has to run without a browser. The browser
+    test is the authority on the real behaviour, and it asserts the same anchors.
+    """
+    cleaned = re.sub(r"[^\w\s-]", "", text.lower(), flags=re.UNICODE).strip()
+    return re.sub(r"[\s-]+", "-", cleaned).strip("-") or "section"
+
+
+def anchors(path: Path) -> set[str]:
+    found: dict[str, int] = {}
+    for heading in HEADING.findall(body(path)):
+        # Markdown emphasis and inline code are not part of the rendered text.
+        plain = re.sub(r"[*`_]", "", heading)
+        base = slug(plain)
+        found[base] = found.get(base, 0) + 1
+    return {name if index == 1 else f"{name}-{index}" for name, count in found.items() for index in range(1, count + 1)}
+
+
+def internal_links(path: Path) -> list[str]:
+    return [
+        href
+        for href in MARKDOWN_LINK.findall(body(path))
+        if not re.match(r"^[a-z][a-z\d+.-]*:", href, re.IGNORECASE) and not href.startswith("//")
+    ]
+
+
+# ── the documentation tree ───────────────────────────────────────────────────
+
+
+def test_the_index_exists_and_names_every_page():
+    """A page nobody links to is a page nobody reads."""
+    assert INDEX.is_file()
+    listed = {
+        (INDEX.parent / href.split("#")[0]).resolve()
+        for href in internal_links(INDEX)
+        if href.split("#")[0].endswith(".md")
+    }
+    unreachable = [page.name for page in pages() if page != INDEX and page.resolve() not in listed]
+    assert unreachable == [], f"not linked from the index: {unreachable}"
+
+
+def test_every_internal_link_and_anchor_resolves():
+    broken: list[str] = []
+    for page in pages():
+        for href in internal_links(page):
+            target, _, anchor = href.partition("#")
+            destination = page if not target else (page.parent / target).resolve()
+            if not destination.is_file():
+                broken.append(f"{page.name} → {href} (no such file)")
+                continue
+            if anchor and anchor not in anchors(destination):
+                broken.append(f"{page.name} → {href} (no such heading)")
+    assert broken == [], broken
+
+
+def test_every_page_starts_with_one_title():
+    for page in pages():
+        titles = [line for line in page.read_text().splitlines() if line.startswith("# ")]
+        assert len(titles) == 1, f"{page.name} has {len(titles)} top-level titles"
+
+
+# ── the vendored renderer ────────────────────────────────────────────────────
+
+
+def test_the_vendored_libraries_are_the_files_that_were_pinned():
+    """A vendored dependency without a recorded checksum is a dependency nobody is
+    reviewing. Replacing one has to be a visible change to this manifest."""
+    manifest = json.loads((VENDOR / "VERSIONS.json").read_text())
+    recorded = {entry["file"]: entry for entry in manifest["libraries"]}
+
+    on_disk = {path.name for path in VENDOR.iterdir() if path.suffix in (".js", ".mjs")}
+    assert on_disk == set(recorded), f"unrecorded vendored files: {on_disk ^ set(recorded)}"
+
+    for name, entry in recorded.items():
+        digest = hashlib.sha256((VENDOR / name).read_bytes()).hexdigest()
+        assert digest == entry["sha256"], f"{name} does not match the pinned checksum"
+        assert entry["version"] in entry["url"], f"{name}: the pinned URL and version disagree"
+        assert entry["license"], f"{name}: no license recorded"
+
+
+def test_the_documentation_view_is_wired_into_the_shell():
+    shell = (REPO / "frontend" / "index.html").read_text()
+    assert 'data-nav="docs"' in shell, "the manuals are unreachable from the navigation"
+    assert '"/docs"' in (REPO / "frontend" / "js" / "app.js").read_text()
+
+
+# ── the policy the view runs under ───────────────────────────────────────────
+
+
+def test_the_script_boundary_is_unchanged_and_only_style_was_relaxed():
+    """The measured cost of rendering diagrams in the browser, held to that cost.
+
+    mermaid needs to style the SVG it builds, which `style-src 'self'` refuses. It
+    does not need to execute generated code, so `script-src` must never acquire the
+    escape hatch that would let injected markup run.
+    """
+    policy = DEFAULT_HEADERS["content-security-policy"]
+    directives = {
+        part.split(" ")[0]: part.split(" ")[1:]
+        for part in (piece.strip() for piece in policy.split(";"))
+        if part
+    }
+    assert directives["script-src"] == ["'self'"]
+    assert "'unsafe-inline'" in directives["style-src"]
+    for directive in ("default-src", "img-src", "connect-src", "font-src"):
+        assert "'self'" in directives[directive]
+        assert "'unsafe-inline'" not in directives[directive]
+    assert directives["frame-ancestors"] == ["'none'"]
+
+
+# ── serving it ───────────────────────────────────────────────────────────────
+
+
+def test_the_application_serves_the_markdown_without_a_session(tmp_path):
+    """Whoever cannot get past the access secret is exactly who needs these pages."""
+    config = Config.from_env({"PHOTO_PIPELINE_DATA_DIR": str(tmp_path / "data")})
+    (tmp_path / "data").mkdir()
+    with TestClient(create_app(config), raise_server_exceptions=False) as client:
+        response = client.get("/docs/index.md", headers={"cookie": ""})
+        assert response.status_code == 200
+        assert "Photo Pipeline documentation" in response.text
+        assert client.get("/docs/overview.md").status_code == 200
+        assert client.get("/docs/nothing-here.md").status_code == 404
+        # The mount is a directory, not a path parameter: nothing above it is reachable.
+        assert client.get("/docs/../pyproject.toml").status_code in (307, 404)
+        assert client.get("/docs/%2e%2e/pyproject.toml").status_code == 404
+
+
+def test_the_image_ships_the_documentation_it_serves():
+    """An image without `docs/` serves an empty manual — and the build context is
+    deny-by-default, so a new directory is excluded until it is named."""
+    assert "\n!docs\n" in (REPO / ".dockerignore").read_text()
+    assert "COPY docs ./docs" in (REPO / "Dockerfile").read_text()

tests/integration/test_installation_manual.py

@@ -0,0 +1,178 @@
+"""US09-02: the installation manual, checked against the thing it describes.
+
+Documentation rots quietly. A setting is renamed, a command grows a flag, an exit
+code changes meaning — and the manual keeps confidently saying the old thing until
+somebody follows it into a bad afternoon. So every fact in it that the code also
+knows is compared with the code, in both directions where both directions are
+meaningful: a setting the manual invents fails, and a setting the manual forgot
+fails too.
+"""
+
+from __future__ import annotations
+
+import re
+import subprocess
+import sys
+from functools import lru_cache
+from pathlib import Path
+
+from photo_pipeline.config import ENV_PREFIX, LEGACY_ALIASES, Config
+
+REPO = Path(__file__).resolve().parents[2]
+MANUAL = REPO / "docs" / "installation.md"
+MAIN = REPO / "photo_pipeline" / "__main__.py"
+
+TEXT = MANUAL.read_text()
+ENV_NAMES = re.compile(rf"{ENV_PREFIX}[A-Z0-9_]+")
+
+# Read by docker-compose.yml, not by Config. They are configuration an installer sets,
+# so the manual documents them; they are simply not application settings.
+COMPOSITION_ONLY = {
+    f"{ENV_PREFIX}IMAGE",
+    f"{ENV_PREFIX}LIBRARY_HOST_PATH",
+    f"{ENV_PREFIX}PUBLISH_ADDRESS",
+    f"{ENV_PREFIX}UID",
+    f"{ENV_PREFIX}GID",
+    f"{ENV_PREFIX}ENV_FILE",  # read before Config exists, so it is not a field
+}
+
+
+def documented_env_names() -> set[str]:
+    return set(ENV_NAMES.findall(TEXT))
+
+
+@lru_cache
+def cli_help(*args: str) -> str:
+    """What the CLI says about itself, asked the way an operator asks."""
+    result = subprocess.run(
+        [sys.executable, "-m", "photo_pipeline", *args, "--help"],
+        cwd=REPO,
+        capture_output=True,
+        text=True,
+        timeout=120,
+        check=False,
+    )
+    assert result.returncode == 0, result.stderr
+    return result.stdout
+
+
+@lru_cache
+def cli_commands() -> frozenset[str]:
+    listed = re.search(r"\{([a-z0-9,\-]+)\}", cli_help())
+    assert listed, f"the CLI listed no subcommands:\n{cli_help()}"
+    return frozenset(listed.group(1).split(","))
+
+
+def cli_flags(command: str) -> frozenset[str]:
+    return frozenset(re.findall(r"--[a-z][a-z-]+", cli_help(command)))
+
+
+# ── settings ─────────────────────────────────────────────────────────────────
+
+
+def test_every_setting_is_documented():
+    """A setting nobody documents is a setting nobody configures deliberately."""
+    expected = {f"{ENV_PREFIX}{field.upper()}" for field in Config.model_fields}
+    missing = sorted(expected - documented_env_names())
+    assert missing == [], f"undocumented settings: {missing}"
+
+
+def test_the_manual_invents_no_settings():
+    unknown = sorted(
+        name
+        for name in documented_env_names()
+        if name.removeprefix(ENV_PREFIX).lower() not in Config.model_fields
+        and name not in COMPOSITION_ONLY
+    )
+    assert unknown == [], f"documented but not a real setting: {unknown}"
+
+
+def test_the_documented_defaults_are_the_real_defaults():
+    """Spot-checked where a wrong default is actively dangerous: the bind address,
+    the trust boundary, and the gate that protects an irreplaceable library."""
+    assert Config.model_fields["host"].default == "127.0.0.1"
+    assert "`PHOTO_PIPELINE_HOST` | `127.0.0.1`" in TEXT
+    assert Config.model_fields["allowed_hosts"].default == ()
+    assert Config.model_fields["require_dry_run_approval"].default is False
+    assert "`PHOTO_PIPELINE_REQUIRE_DRY_RUN_APPROVAL` | `false`" in TEXT
+
+
+def test_every_secret_is_marked_as_one():
+    for field in ("access_secret", "vision_api_key", "immich_api_key"):
+        name = f"{ENV_PREFIX}{field.upper()}"
+        row = next(line for line in TEXT.splitlines() if line.startswith(f"| `{name}`"))
+        assert "secret" in row.lower(), f"{name} is not marked as a secret"
+
+
+def test_the_legacy_aliases_are_documented():
+    """An operator with an existing photo_analyzer.env needs to know it still works."""
+    for alias in LEGACY_ALIASES:
+        assert alias in TEXT, f"legacy alias {alias} is undocumented"
+
+
+# ── commands ─────────────────────────────────────────────────────────────────
+
+
+# The manual is an installation and operations manual, not a command reference: these
+# are the commands an installer actually runs, and every one of them must exist.
+OPERATIONAL = ("migrate", "serve", "worker", "backup", "verify-backup", "restore", "diagnostics")
+
+
+def test_every_command_the_manual_tells_you_to_run_exists():
+    missing = [name for name in OPERATIONAL if name not in cli_commands()]
+    assert missing == [], f"the manual names commands the CLI does not have: {missing}"
+    undocumented = [name for name in OPERATIONAL if not re.search(rf"\b{re.escape(name)}\b", TEXT)]
+    assert undocumented == [], f"operational commands the manual omits: {undocumented}"
+
+
+def test_every_documented_flag_exists_on_the_command_it_is_shown_with():
+    for command, flag in (
+        ("backup", "--reason"),
+        ("backup", "--keep"),
+        ("restore", "--into"),
+        ("worker", "--allow-legacy"),
+        ("serve", "--allow-legacy"),
+    ):
+        assert flag in cli_flags(command), f"{command} has no {flag}"
+        assert flag in TEXT, f"{flag} is undocumented"
+
+
+# ── exit codes ───────────────────────────────────────────────────────────────
+
+
+def test_every_documented_exit_code_is_one_the_cli_can_return():
+    documented = {int(code) for code in re.findall(r"^\| `(\d)` \|", TEXT, re.MULTILINE)}
+    returned = {int(code) for code in re.findall(r"^\s+return (\d)$", MAIN.read_text(), re.MULTILINE)}
+    assert documented, "no exit codes are documented"
+    assert documented <= returned | {0}, f"documented but unreachable: {sorted(documented - returned)}"
+
+
+def test_every_refusal_exit_code_is_documented():
+    """0 is success and 1 is 'it said why'; every other code is a specific refusal an
+    operator will meet at startup, and meeting an undocumented one is the worst case."""
+    returned = {int(code) for code in re.findall(r"^\s+return (\d)$", MAIN.read_text(), re.MULTILINE)}
+    documented = {int(code) for code in re.findall(r"^\| `(\d)` \|", TEXT, re.MULTILINE)}
+    missing = sorted(code for code in returned if code not in documented and code != 0)
+    assert missing == [], f"undocumented exit codes: {missing}"
+
+
+# ── the promises the manual makes ────────────────────────────────────────────
+
+
+def test_the_manual_carries_no_credential_shaped_example():
+    """The repository's own scanner refuses these in a commit; a manual is exactly
+    where a real-looking one gets copied from."""
+    suspicious = re.findall(
+        r"(?i)(api[_-]?key|secret|token|password)\s*[=:]\s*[\"']?([A-Za-z0-9_\-]{12,})",
+        TEXT,
+    )
+    assert suspicious == [], f"credential-shaped example: {suspicious}"
+
+
+def test_the_manual_states_the_invariants_an_installer_must_not_break():
+    for invariant in ("_IGNORE/", "One writer", "EXIF is verified before upload"):
+        assert invariant in TEXT, f"the manual does not state: {invariant}"
+
+
+def test_the_manual_is_reachable_from_the_index():
+    assert "installation.md" in (REPO / "docs" / "index.md").read_text()

tests/integration/test_user_manual.py

@@ -0,0 +1,172 @@
+"""US09-04: the user manual, checked against the application it describes.
+
+The manual's most perishable claim is its error catalogue: a code renamed in a route
+leaves a page confidently explaining something that can no longer happen, and the
+operator meeting the new code finds nothing. So the catalogue is compared with the
+codes the application can actually emit, in both directions.
+
+The screenshots are generated and checked by
+``tests/e2e/test_user_manual_screenshots.py``.
+"""
+
+from __future__ import annotations
+
+import re
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[2]
+DOCS = REPO / "docs"
+STAGES = DOCS / "stages"
+PACKAGE = REPO / "photo_pipeline"
+ERRORS = (DOCS / "errors.md").read_text()
+ALL_DOCS = "\n".join(path.read_text() for path in DOCS.rglob("*.md"))
+
+# The shapes an error code is emitted in. Everything the API returns goes through one
+# of these, so the set they find is the set an operator can meet.
+EMITTERS = (
+    re.compile(r'_error\(\s*\d+,\s*"([a-z_]+)"'),
+    # The status may be a literal or an exception's own code, so match either.
+    re.compile(r'_envelope\(\s*[\w.]+,\s*"([a-z_]+)"'),
+    re.compile(r'"code":\s*"([a-z_]+)"'),
+    re.compile(r'code="([a-z_]+)"'),
+    re.compile(r'Refusal\(\s*\d+,\s*"([a-z_]+)"'),
+)
+
+# Codes raised deep in a service and mapped to a response by its route; they are what
+# the browser shows, so the manual owes the reader an entry.
+SERVICE_CODES = {
+    "lock_held",
+    "path_not_allowed",
+    "rename_recovery_required",
+    "stale_preflight",
+    "access_denied",
+    "too_many_attempts",
+}
+
+STAGE_PAGES = (
+    "inventory",
+    "duplicates",
+    "safety",
+    "analysis",
+    "albums",
+    "renames",
+    "uploads",
+    "archive",
+    "diagnostics",
+)
+
+
+def emitted_codes() -> set[str]:
+    found: set[str] = set()
+    for path in PACKAGE.rglob("*.py"):
+        text = path.read_text()
+        for pattern in EMITTERS:
+            found |= set(pattern.findall(text))
+    for code in SERVICE_CODES:
+        assert re.search(rf'"{code}"', "\n".join(p.read_text() for p in PACKAGE.rglob("*.py"))), (
+            f"{code} is documented as a service code but no longer exists"
+        )
+    return (found | SERVICE_CODES) - {"code"}
+
+
+def documented_codes() -> set[str]:
+    return set(re.findall(r"`([a-z][a-z_]{3,})`", ERRORS))
+
+
+# ── the error catalogue ──────────────────────────────────────────────────────
+
+
+def test_every_error_the_application_can_emit_is_documented():
+    missing = sorted(emitted_codes() - documented_codes())
+    assert missing == [], f"undocumented error codes: {missing}"
+
+
+def test_the_catalogue_documents_no_code_that_cannot_happen():
+    """Backticked snake_case in the catalogue is either a code, a setting, or one of
+    the handful of prose terms below."""
+    prose = {
+        "diagnostics",
+        "dry_run",
+        "approve_dry_run",
+        "current_path",
+        "archived_online",
+        "archived_offline",
+    }
+    settings = set(re.findall(r"PHOTO_PIPELINE_[A-Z_]+", ERRORS))
+    invented = sorted(
+        code
+        for code in documented_codes()
+        if code not in emitted_codes()
+        and code not in prose
+        and f"PHOTO_PIPELINE_{code.upper()}" not in settings
+    )
+    assert invented == [], f"documented but not emitted anywhere: {invented}"
+
+
+def test_the_protective_refusals_are_explained_as_intentional():
+    """These are the ones a reader is most likely to mistake for a broken
+    application, which is exactly when they start working around them."""
+    for code in ("lock_held", "rename_recovery_required", "stale_preflight", "not_runnable"):
+        row = next(line for line in ERRORS.splitlines() if line.startswith(f"| `{code}`"))
+        assert len(row.split("|")) >= 4, f"{code} has no cause and remedy"
+
+
+# ── the stage pages ──────────────────────────────────────────────────────────
+
+
+def test_there_is_one_page_per_workflow_stage():
+    missing = [name for name in STAGE_PAGES if not (STAGES / f"{name}.md").is_file()]
+    assert missing == [], f"stages without a page: {missing}"
+
+
+def test_every_stage_page_answers_the_four_questions():
+    """The shape is the point: a page that skips 'what it changes' is the page
+    somebody needed."""
+    for name in STAGE_PAGES:
+        text = (STAGES / f"{name}.md").read_text()
+        for question in ("What it is for.", "What you decide.", "What it changes.", "What it refuses."):
+            assert question in text, f"{name}.md does not answer: {question}"
+
+
+def test_every_stage_page_shows_a_screenshot():
+    for name in STAGE_PAGES:
+        text = (STAGES / f"{name}.md").read_text()
+        assert re.search(r"!\[[^\]]+\]\(\.\./images/[a-z-]+\.png\)", text), (
+            f"{name}.md carries no screenshot"
+        )
+
+
+def test_the_guided_pass_names_the_irreversible_stages():
+    first_pass = (DOCS / "first-pass.md").read_text()
+    for stage in ("renames", "uploads", "archive"):
+        assert f"stages/{stage}.md" in first_pass
+    assert "point" in first_pass.lower() and "no return" in first_pass.lower()
+
+
+def test_recovery_covers_each_interruption_the_application_can_survive():
+    recovery = (DOCS / "recovery.md").read_text()
+    for topic in (
+        "interrupted rename",
+        "uncertain upload",
+        "failed migration",
+        "restored backup",
+    ):
+        assert topic in recovery.lower(), f"recovery does not cover: {topic}"
+
+
+def test_the_manual_is_reachable_from_the_index():
+    index = (DOCS / "index.md").read_text()
+    for page in [f"stages/{name}.md" for name in STAGE_PAGES] + [
+        "first-pass.md",
+        "errors.md",
+        "recovery.md",
+    ]:
+        assert page in index, f"{page} is not linked from the index"
+
+
+def test_the_screenshots_are_declared_as_generated():
+    """The allow list had to be widened for them, so the reason has to be visible
+    where the widening is."""
+    config = (REPO / "work_item" / ".work-item.yml").read_text()
+    assert "docs/images/**" in config
+    assert "test_user_manual_screenshots.py" in config, "no note saying who generates them"

tests/story_traceability.json

@@ -193,13 +193,24 @@
     "US08-05": [
       "tests/integration/test_container_gate.py",
       "tests/e2e/test_phase_h_container.py"
+    ],
+    "US09-01": [
+      "tests/integration/test_documentation.py",
+      "tests/e2e/test_docs_ui.py"
+    ],
+    "US09-02": [
+      "tests/integration/test_installation_manual.py"
+    ],
+    "US09-03": [
+      "tests/integration/test_architecture_overview.py",
+      "tests/e2e/test_docs_ui.py"
+    ],
+    "US09-04": [
+      "tests/integration/test_user_manual.py",
+      "tests/e2e/test_user_manual_screenshots.py"
     ]
   },
   "planned": [
-    "US09-01",
-    "US09-02",
-    "US09-03",
-    "US09-04",
     "US09-05"
   ],
   "_planned_comment": "Accepted backlog stories that are not implemented yet. The release gate (US07-07) requires every story file to be either mapped to tests or listed here, so an unimplemented story is a visible decision rather than a hole in the matrix."

work_item/.work-item.yml

@@ -16,6 +16,9 @@ safety:
   max_file_bytes: 5000000
   allow:
     - tests/fixtures/**
+    # Generated by tests/e2e/test_user_manual_screenshots.py from a synthetic fixture
+    # library, never a real photo. The deny list below blocks images by default.
+    - docs/images/**
   deny:
     - _IGNORE/**
     - "**/_IGNORE/**"